Thomas James Jagodowski tries not to worry his parents. So when the mystery symptoms he'd been experiencing for months—the dizziness, the loss of coordination, the confusion, the constant sense of rocking back and forth—got especially bad one evening in the summer of 2000, he didn't call them. A fixture of Chicago's comedy community, Jagodowski has plenty of close friends, but he didn't call any of them; everyone he could think of was performing in a show somewhere. And he didn't call 911 either. Instead he grabbed his wallet, so his body could be identified, and went out to the sidewalk, where he waited to die. "I stood on the corner of Hamilton and Addison for half an hour and I didn't die," he says. "So I went to go rent a movie."

Since then the 36-year-old improviser has grown even more blase about the unnamed ailment that has now dogged him for the past nine years. No neurologist, otolaryngolist, migraine specialist, acupuncturist, nutritionist, or chiropractor has been able to pinpoint a cause or offer a cure. "None of whatever they've prescribed or recommended has done anything," he says, "but it's been going on for so long now that I just kind of work around it."

Navigating that kind of neurological landscape would be a formidable task for anyone, let alone someone who needs ninja-quick instincts to earn his living. Jagodowski and actor David Pasquesi have performed long-form improv on Wednesday evenings since 2002 in iO's Cabaret Theater, where their show, TJ & Dave, has gained something of a cult following—if any more chairs were crammed in there during the 11 PM performances, which sell out nearly every week, the fire marshals would probably freak out. (The show went on summer break Wednesday.) TJ & Dave also does well in New York, where since 2006 Jagodowski and Pasquesi have taken it about once a month. The New York Times has called it "observant, complex, and frequently enormously funny," praising the pair's "onstage chemistry, comic instincts, and never-miss-a-beat improvisation abilities."

Jagodowski has also gained some prominence with his improvised appearances on commercials for Sonic, a national fast-food chain that's soon to open its first Illinois franchise in Aurora. "It pays my bills for a ridiculously little amount of work," he says. He just bought a condo with Sonic money. In addition to TJ & Dave, he performs as part of the iO team Carl & the Passions and the Annoyance Theatre's Chicagoland team, and he's appeared in locally shot films such as Stranger Than Fiction (where he plays one of Will Ferrell's coworkers at the IRS). He has time to see his friends' shows, take his grandma dancing at the Green Mill when she comes to town, and read books that he sometimes autographs to himself from the author afterward (Ernest Hemingway: "Stay macho"). "It's a pretty great life," he says.

But as well as he's learned to manage the mysterious affliction, it hasn't gone away. And in certain situations, it can produce a smothering anxiety that's far harder on Jagodowski than regular stage fright. Oddly, improv doesn't bring it on—but scripted material does. So though he'd like to do plays, he says, "I end up asking my agent for one-line parts or things that don't have talking in them," or for special situations such as Stranger Than Fiction, in which he was allowed to improvise his performance. Otherwise, most stage and film work is out.

Despite the constraints the condition has placed on his career, Jagodowski seems remarkably stoic about it. "For the first year or so, there were some times I got mad or I got a little sad," he says, and early on he feared becoming "a shut-in eating macrobiotic food." But now he tries not to focus on it too much, and remains grateful that it hasn't taken away his ability to improvise. "It left me with the thing that I loved the most," he says.

Jagodowski grew up in Holyoke, Massachusetts, the oldest son of a plumber and a grammar school teacher. There were no performers in his family. Instead, he says, "we have ski shop owners and old soldiers." His only early brush with the stage came in eighth grade, when he was cast in a musical at his Catholic school. "I had one rehearsal with the lady who was supposed to play piano," he says. "They didn't say this, but I know this is true—I was so bad they canceled the whole thing. Then our high school didn't have plays, so I didn't really think about it."

For one thing, he was too busy studying. Jagodowski was the salutatorian of his graduating class. "This is how dorky I was—I gave up a study period to voluntarily take economics," he says. "I don't know why I wanted to learn about economics. I think because of Family Ties"—and the sitcom's junior-financier character, Alex P. Keaton. Having skipped fourth grade, he entered Syracuse University on his 17th birthday. That's where he started learning how to fail.

"I was an economics major when I started, and I got a 16 on my first test," Jagodowski says. "If that had happened when I was in high school, it just would have been so awful." Now it felt oddly liberating. "I walked around with my little blue book for a while [and thought], 'The sky's not falling. I'm not having a heart attack. In fact, I feel kind of good. I can suck, and it's going to be all right.'" On another occasion, in what sounds like a scene straight from TJ & Dave, he tried to cram a term's worth of Shakespeare plays into two consecutive all-nighters. He ended up falling asleep on his side outdoors and sunburned half his face. He woke up after his exam had started, and then only because he was hit with a Frisbee.

But the low point of his college career had nothing to do with academics. It had to do with a vending machine. "I went to buy some Munchos, and it didn't give me my Munchos," he says. "So I went around to the back of the machine and kind of jostled it. It started to fall. It made total sense at the time to think 'Boy, that's going to be loud. I better catch it.'" The machine landed on his leg, which—when he extricated himself and tried to stand up—made a noise "like a sock full of billiard balls." His tibia and fibula were broken and bone pierced his skin. "I got a couple of plates and a bunch of screws put in, the whole shebang," he says. Later staph set in, and he came close to losing the leg. It's a story he's shared onstage during the monologue-driven Armando Diaz Experience show at iO.

Jagodowski didn't get into any lasting trouble; he didn't even drink when he was underage because he thought it would disappoint his family. He wound up with a double major in English and TV/radio/film, planning to become a producer like his friend Lisa Masseur (now executive producer at Chicago's Radar Studios). Despite appearing in a few of his classmates' student films, he still felt no particular urge to perform.

After graduating in 1992, he moved to Chicago. Masseur was already here and had said he could sleep on her couch for a while. She also got him his first job in entertainment, as a production assistant on the 1993 TV series The Untouchables. He hated it. "Most of it's just standing outside telling people to shut up," he says. "And it seemed like the biggest job of the highest producer was OKing the crew to work through a meal break. If that's succeeding in production, that doesn't sound like fun."

Besides, Masseur knew he could do more. "TJ was obviously just so funny. He was always 'that funny guy,'" she says. "I remember when he was living with us I took him to a party where he didn't know anybody, and I'm telling you, he started doing a skit. He pretended he had Tourette's." She took Jagodowski to Second City for the first time, to see Take Me Out to the Balkans, a main-stage show with a cast featuring Stephen Colbert, Steve Carell, and Amy Sedaris. During the show she turned to him and said, "This is what you should be doing."

Jagodowski calls it a "Bible-hits-you-in-the-back-of-the-head kind of moment." The improv onstage "was so alive and momentary, and it was funnier and more interesting than the scripted stuff. It just felt like it hit me somewhere I hadn't been hit before. I thought, 'If I don't try and do this I'll never be happy.'" A couple months later, Masseur nudged him into taking an improv class at Second City. Before his first class, he sat in a bar with a notebook and wrote: "So it begins."

If Jagodowski's college follies hadn't killed off his inner salutatorian, improv training did its best to finish the job. He quickly learned that left-brain thinking gets you nowhere in improv. "It was the first time I heard the word 'clever' used as an insult," he says. "The whole thing is, in a weird way, to be OK with being unprepared. If you can get to the point where you can realize that the moment is going to take care of you, and that your thinking is only going to get in the way of that, then you're going to be fine." That moment-to-moment approach spilled over into his life offstage. "I didn't really think about how it was supposed to work out, or about making a living at it," he says. "I just knew that that was the best three hours of the week."

By 1995 Jagodowski had earned a spot on iO's Georgia Pacific team, where he got to know the man who would become his best friend, Jack McBrayer. "All of us were always clamoring to do scenes with him," says McBrayer, who now plays Kenneth the page on NBC's 30 Rock. "If he asked me to walk over hot coals, I would do it. He always played with such confidence, even early on." Peter Grosz, another close friend from those days who now writes for The Colbert Report and appears with Jagodowski in the Sonic commercials, echoes those sentiments: "More than anyone I know, he has such ease with which he performs."

Jagodowski's talent is supported by his dedication to supporting his fellow performers. Onstage, rather than frantically trying to come up with lines to elicit instant laughs, he's intently listening to and watching the people he's improvising with, letting the relationship between the characters play out in an unforced way. As he emphasized recently to one of the classes he now teaches at iO, the audience goes away after a performance but your fellow players remain, and "those are the eyes you have to make sure you can stare into at the end of the evening." It's that support, in part, that makes so many improvisers eager to perform with him. "Improvising with TJ is incredibly easy and freeing," Grosz says, "because he does so much for the other person. I'm often surprised at the places that I get to go when I'm improvising with him."

Class by class, show by show, Jagodowski worked his way up to a spot in one of Second City's touring companies in 1997. His family was pleased, if puzzled. "We had to go through that discussion everyone goes through," he says. "'You're doing stand-up?' 'No, we make stuff up. You do make-believe for half an hour.'" His mother in particular rallied beautifully. When she found out Jagodowski's company would be performing near Holyoke, she called him and announced, "We have 42 people coming on a bus. And those are the first 42 who called back."

In 1998 Jagodowski joined the influential iO team JTS Brown, which among others featured Grosz, John Lutz (who now plays Lutz on 30 Rock), Ike Barinholtz (who'd go on to MADtv), and Jason Sudeikis (Saturday Night Live, 30 Rock). (They reunite this Saturday at the Lakeshore Theater as part of the Chicago Improv Festival.) That same year he made it to Second City's main stage, where he helped create a well-received sketch show called The Psychopath Not Taken. A few months after opening night, he was onstage when the illness that would change his life first hit. "Everything I was seeing flipped through the bottom and back through the top, sucked back to a pinhole, and then zoomed back forward," he says. "From then on, there was just this constant sense of rocking back and forth." Between acts he went to the hospital. "They diagnosed it as vertigo, which should last six to eight weeks, and they put me on this souped-up Dramamine. It didn't do anything."

For a couple weeks he tried to continue performing. One night he went onstage only to blank out in the middle of a scene. He didn't know what to do except walk off. "I looked at the running order [of the show's scenes] and didn't recognize a single thing on it. If it had said Richard III I would have gone, 'OK, I don't know any of the words to that either.'" Each night McBrayer, his understudy, waited with him in the wings until showtime, when Jagodowski would decide if he could go on or not. "It was an awful thing to do to a cast," Jagodowski says. "If they can't rely on you to do your stuff, then you can't stick around." He quit. He tried again in 2001, with a brief return to Second City's lower-profile E.T.C. stage, but once more had to leave before the show's run ended.

For about a year and a half after the symptoms started, pretty much anything could trigger them—crossing the street, going to the grocery store. "Everything back then was a bit nerve-wracking," Jagodowski says. After that, it was flying and scripted material, and now, well, it's pretty much just scripted material.

Jagodowski calls himself "a bit of a complainer." But Masseur doesn't remember him even discussing his symptoms in any detail with her. "He didn't really talk too much to me about it," she says. "He deals with everything on his own. I think that's just part of his personality—'Oh yeah, I have this thing, no big deal.'"

McBrayer agrees. "Every now and then he lets his guard down," he says. Still, "he internalizes so much of it. For the most part, he doesn't want to burden anybody. He's just so in tune to other people's feelings." David Pasquesi, who's Jagodowski's most frequent improv partner these days, adds, "Very rarely he'll say he's having some sort of day. Maybe it happens more often and he just doesn't tell me."

One of the condition's most frustrating aspects is Jagodowski's not knowing to what extent it's psychosomatic. "I don't know what part of it is physical or is psychological, or what started what," he says. "I know it wasn't nerves when it happened. I was really happy to go to work and loved being there." But over time, he acknowledges, anxiety about the symptoms may have come to help perpetuate them. "I tried a therapist, to try and go at it in that fashion," he says. It didn't help. "When all hell's breaking loose, you can't get to that part of your brain. Like, 'Oh, I'm supposed to breathe slow,' and the more you think about breathing slow, you realize you're breathing really fast. It's tough to access that part [of your mind] when you're really in an anxious state." He prefers not to address it pharmaceutically either.

In the end, after all the doctor visits, Jagodowski decided that all he could do was get used to the disorientation and avoid whatever made it worse—including scripted material. In improv, not only can he invent a reason for his character to sit down or walk offstage if he feels woozy, but he has to be so engaged and present that there's no room for anxiety to blossom. With scripted material, his mind has more space to freak out in. He did force himself to accept a small part in the 2005 John Cusack vehicle The Ice Harvest, directed by Harold Ramis. "Everybody on it could not have been cooler or more pleasant," he says. "Mr. Ramis could not have been nicer or better at what he does. And I absolutely hated it. It was a terrifying experience."

Understandably, after almost a decade of dealing with the illness, he tries not think about it too much. But when Saturday Night Live came calling in 2002, it was hard to think of anything else.

SNL's producers were looking for someone to replace Will Ferrell. They invited Jagodowski and McBrayer to audition, along with several other male improvisers from Chicago, New York, and Los Angeles. Jagodowski had serious doubts from the beginning, telling SNL writer/performer Tina Fey (a Second City and iO alum), "Even if I were lucky enough to get this job, I don't think I could do it." But she and McBrayer persuaded him to at least audition.

"TJ, of course, shone," McBrayer says. Jagodowski was invited back for a final tryout, to consist of a solo performance that would include impressions. But "there was just no way," he says. He's never enjoyed performing alone, he doesn't do impressions, and to top it off there was the anxiety scripted material had come to spark. "I wish it was some political stance or creative disagreement, but it's not," he says. "Just wuss. Thinking about it now, I can feel my legs want to start shaking." He bowed out.

Jagodowski expresses not a trace of regret. Nor does he speculate how that final audition might have altered his career. Many of his improviser friends, including McBrayer and Grosz, have left Chicago for bigger ponds, and no one doubts that Jagodowski has the talent to do likewise. But no one criticizes his decision.

"We all just want him to be happy, in whatever that means," McBrayer says. "I'm completely content as long as he is. The old boy is doing good, especially financially. [But] the minute he decides that he's not happy, I am going to do anything I can do to help him out." Masseur is a little less philosophical. "In my mind, he should be on SNL, he should be in movies," she says. "I don't know if he has those aspirations, but I have those aspirations for him."

The upshot: Chicago has lost one fewer talented performer and retained one of its best long-running long-form improv acts. Around the time of the SNL auditions, Jagodowski met Pasquesi, a fellow Second City alum who had trained with the legendary Del Close. Pasquesi was looking for someone who shared his love of the kind of improv he says Close taught him, "slow comedy" that seeks to be genuine instead of witty and to discover scenes instead of inventing them. The goal, Pasquesi says, is to "have the faith that if I just respond honestly to the very next little moment the story is going to take care of itself." In 2002 he and Jagodowski began performing on Wednesday nights at iO, where they've been ever since.

Before a typical TJ & Dave show, Jagodowski and Pasquesi warm up—if you can call it that—by chatting in iO's small green room, where the decor consists of a filing cabinet and a couch that looks like someone tried to gut it with a butter knife. Jagodowski does a few back and hamstring stretches, a cigarette hanging from the corner of his mouth. When they bound onstage it's to the thumping beat of the Ike Reilly Assassination song "I Don't Want What You Got (Goin' On)." The two stand and beam at the audience, Jagodowski shading his eyes from the stage lights and looking uncertain but happy, wearing a gap-toothed grin as he scans the crowd. When the song ends, one of them says, "We are really looking forward to improvising for you. Trust us, this is all made up." The lights dim.

When they rise a moment later, Pasquesi and Jagodowski have turned to look at each other. One of them eventually says something—maybe "Do they still call it dope?" or "The ping-pong table is fucked." From there a play blossoms, with both men playing pedestrian characters (impatient businessman, barista) as well as outlandish ones (pet groomer cum drug-dealer, "half-retarded" mailroom clerk). Because the scenes emerge so seamlessly, and because Pasquesi and Jagodowski don't take audience suggestions, they're sometimes accused of writing their material ahead of time. "We take it as a wonderful compliment," Pasquesi says. Some 45 to 65 minutes later, the stage manager cuts the lights after whatever line seems like a good closer.

Though they continue to perform TJ & Dave in New York regularly, Pasquesi and Jagodowski have no plans to move the show there, or to Los Angeles. "Those cities are for people with goals," Jagodowski jokes. "I don't mean that. But I think I have one move left, and that's back to New England when I'm old to die." So what does he want? "I want to keep on improvising. I'd like to be a husband and a father at some point. I'm not a real aspirational cat."

But in a way he is. He might not care if he ever makes it onto national television, but you'd be hard put to find improvisers more ambitious about bettering their craft than he and Pasquesi are. "I watched an interview one time with Bjork, and she had just done that movie Dancer in the Dark," Jagodowski says. "She said, 'I didn't really enjoy it much. I want to focus on my music. And if I keep on doing it every day for the next 30 years, I think I'll get closer to the kind of music I want to make.'" That sounds about right. If we did this every week for the next 30 years, we'd probably get a lot closer to doing it right." v

To watch video of TJ Jagodowski in action with TJ & Dave, find this story at chicagoreader.com.