James Hinchcliffe learned long ago that there’s a new challenge around every corner in the NTT IndyCar Series.

We’re not talking about a gust of wind, a temperature change or dirty air that keeps the full attention of the Arrow Schmidt Peterson Motorsports driver on the racetrack. Hinchcliffe, a six-time INDYCAR race winner and pole-sitter in the 2016 Indianapolis 500, is a master at that stuff. The race car is his safe haven.

But he’s got to stay sharp everywhere else, too, because an old pal could be lurking with a practical joke. Hinchcliffe and veteran mechanic Mike Miller of Andretti Autosport have waged a years-long battle involving everything from a remote-operated horn blasting in the middle of the night to a missing toilet seat.

In a sport where the serious business of speed and safety is paramount, a little levity can be a great stress reliever. Just don’t tell Hinchcliffe that the tension eases when he steps out of his Dallara.

“I live in a constant state of fear that Miller is right around the corner with some prank,” Hinchcliffe said. “Getting in the race car is actually my relaxation.”

There’s hardly a driver or crew member who hasn’t been on the receiving end of a joke. Unless they were the perpetrator.

Early this season at Circuit of The Americas in Austin, Texas, several drivers who’d taken part in a news conference returned to their scooters parked outside the media center and found all the keys removed. The No. 1 suspect was Hinchcliffe.

Years ago, the late Dan Wheldon had all of his left shoes mailed to the U.S. during a race week in Japan. Know anything about that, Tony Kanaan?

Conor Daly once returned from an Indy 500 promotional tour to find his motorhome at Indianapolis Motor Speedway filled with balloons and cups of water. For a long time he suspected the usual characters -- especially Kanaan and/or Hinchcliffe – before learning some of his own crew at A.J. Foyt Racing did it.

A few years ago at a benefit golf tournament, an unsuspecting mechanic found his own truck on display as a hole-in-one prize.

Sage Karam bragged to veteran Chip Ganassi Racing teammates in 2015 about the cool black Camaro he was given by Chevrolet to drive around Indy for the month, but he also made the huge mistake of chiding the elder drivers on the team about the “family guy” SUVs they were driving.

Then Karam learned one day after practice that his personal ride had been transformed into the prettiest pink muscle car in town. Turned out those family guys – Scott Dixon and Kanaan, with help from retired driver Dario Franchitti – weren’t too old to humble the kid by having the black Camaro wrapped completely in pink. They made Karam drive around Indy all month in the Camaro, which had a sign in the back window that read, “Honk if you think I’m sexy.”

A lot of guys did honk.

“Then they’d pull beside the car and see that it was me, a dude, driving,” Karam said. “It was quite painful but actually a lot of fun. It was a prank but it turned into a cool thing and, at the end of the day, I ended up kind of rocking it.”

Rarely does a prank go without retribution, and the masters recently have been Hinchcliffe and Miller, the veteran mechanic who has become known as the king of INDYCAR pranksters. Their battle royale started when Hinchcliffe drove for the Andretti team from 2012-2014, and it has escalated since.

“There was a lot of folklore from that group about what it was like back in the good old days at Team Green and Forsythe Racing, where a lot of those guys worked,” Hinchcliffe said. “We used to hear a lot of stories about the things they pulled, and a couple of guys in particular usually were involved, Miller being one of them. Miller’s main henchman is (Andretti mechanic) Neil Campbell, and the two of them usually are up to no good.”

Did you hear about the remote-operated train horn under the seat of a golf cart? Hinchcliffe did, loud and clear, one day at IMS when it nearly jolted him out of that seat. He knew immediately that it was Miller’s work, and that it deserved a response.

“I couldn’t remove the horn from under the seat, so I just removed the whole seat and I threw it under Marco (Andretti’s) bus and waited for him to come back from an event,” Hinchcliffe said. “We got Marco.”

Hinchcliffe then went to dinner with Daly and Alexander Rossi, thinking the horn had blared for the final time. Wrong.

“Rossi told Miller where we were eating,” Hinchcliffe said. “Miller got his hands on the horn again and drove out to where we were and put it under my car. We thought we had gotten rid of it, but I open my car door and this thing starts going off again.”

Miller also was the first person Hinchcliffe suspected – correctly -- when he returned from a promotional event three years ago in St. Petersburg to learn his motor scooter wasn’t where he’d left it at the bottom of a pedestrian bridge. It had been moved atop the bridge.

“A bike in the middle of a bridge is not something you can get down by yourself, so I walked back,” Hinchcliffe said. “And then I saw all my old crew, Miller being the ringleader, pointing and me and laughing.”

Retaliation occurred a few weeks later at Phoenix.

“I broke into Miller’s hotel room while he was sleeping and poured a garbage can of ice water on him,” Hinchcliffe said. “He didn’t know what had happened, which made it even funnier.”

Of course, Miller answered that wakeup call. The next month at IMS, Hinchcliffe returned to his motorhome in the infield bus lot to learn the toilet seat was missing. A couple of days later, as Hinchcliffe took part in a team debriefing after practice, a courier interrupted the meeting and handed him a package. It was the toilet seat.

“I owe him a couple,” Hinchcliffe said. “But as much as I hate to admit it, he’s better at it than I am.”

Besides being a highly respected mechanic, Miller has such a reputation as a prankster that he’s blamed for some he didn’t do.

“The one on Conor Daly had my name written all over it, and I had to swear on the Bible and my two kids that I had nothing to do with it,” Miller said. “And they still didn’t believe me.”

Hinchcliffe’s favorite prank involved an elaborate scheme that messed with the mind of an Andretti Autosport mechanic. Hinchcliffe said Miller was involved, as was George Klotz, now team manager at A.J. Foyt Racing, and even some wives.

“They somehow managed to get hold of the keys to the guy’s truck,” Hinchcliffe said. “At lunch they would move it to a different parking spot, or if he parked it forwards they would park it backwards. It was really freaking this guy out. Then they started going to his house early in the morning before he left for work and doing the same thing in his driveway. This guy was totally, totally sideways about the whole thing.”

Added Miller: “Everybody had a key so he never found out who it was. We moved it every other day. Whenever we were out of town we had a couple of our wives move the car, so he had no idea who (was doing it).”

If that didn’t bewilder the poor guy, what happened as he left with the team for a race put him over the edge.

“They often carpool to the airport, so George (Klotz) was supposed to pick him up at 6 o'clock in the morning,” Hinchcliffe said. “Well, somebody swung by at 5 o’clock, stole the truck and parked it in a place where they knew they'd be driving by to get to the airport.”

And on the truck they placed huge “For Sale” sign on the windshield with the mechanic’s cell phone number.

“When they show up to pick him up, he comes out of his house and freaks out because his truck is missing,” Hinchcliffe said. “George says, ‘We’ve got to go! We can’t miss the flight. We’ll figure it out later.’

“The guy is just apoplectic at this point. He’s looking forlornly out the window as they’re driving to the airport and sure enough, there’s his truck sitting there with a giant ‘For Sale’ sign. His cell phone was ringing off the hook for the next three days.”

In this business, it’s wise to laugh at yourself as much as you laugh at others because, as Hinchcliffe has learned, the next one could be on him. Or maybe it’ll be on his old friend Miller.

Hinch won’t say what his next move will be other than there will be one, even if he must wait until next May.

“Miller does have a motorhome and for the last week (in May) he parks in a lot across the street (from IMS),” Hinchcliffe said. “I know where it is, so he’d better sleep with one eye open.”