“The Flash” begins its third season on the CW this month, with Tom Cavanagh playing multiple versions of his character, thanks to the series’ presentation of time-travel and alternate universes. Cavanagh spoke recently with Variety about the series, his co-workers and his favorite charity.

What changes will we see this season?

Well, the biggest change is something I can’t talk about because of the Warner Bros. snipers atop the turrets around me.

You’ve played many iterations of “The Flash” characters Dr. Wells and Eobard Thawne. Do you have a favorite?

I get to invent a number of iterations of them. I believe this will be my fifth one, and it is a privilege. I don’t know if it’s apt to describe it in the realm of favorite, but the starting point for me for everything is Eobard Thawne and the Reverse-Flash. That was my starting point and I’m sure, at some point, that’ll be my return point as well.

Kevin Smith is working on the show. How has that changed things?

Kevin came to set armed with 1,000 Timbits, which are the tiny version of the Tim Horton’s doughnuts, which is the most populous coffee chain up here in Canada, and Kevin carted 1,000 Timbits into set, and I think there’s three words that best describe that action: bless his heart. He’s one of the most gregarious, generous and accomplished people I’ve ever met in the entertainment world. He’s so engaging and genuine, and his energy lifts everything in whatever job he happens to be doing at the moment. He’s one of a kind, and we’re so fortunate to have aligned ourselves with him. The first time he saw Grant (Gustin) in the Flash suit, Kevin took three steps backward and clutched his heart. We were like, “Oh, no, is Kevin Smith having a heart attack?” He’s like, “No, man, this is my first time witnessing the suit in person.” He was having a complete fanboy moment. You want to work hard for a guy like that, who’s just so happy to be there.

“The Flash” and “Supergirl” will be having a musical crossover this season. What was your reaction?

Isn’t this the domain of season seven, grasping at straws? We’re in season three! We seem to be doing just fine. Why do you want to jeopardize this by having people opening their mouths in song? But I would call that respect for the comic-book world, for the people who are keeping our show alive, for the fans. It’s like, “Look, we’re not sitting back and repeating the pilot,” so I guess you can make the argument that having a singing episode is just one more version of us moving things along and moving forward. I would say the lynchpin to the success of the musical episode for us is to go through Carlos Valdes [who plays Cisco Ramon on the show]. He is incredible. Again, I think it’s a sign of respect that we’re willing to attempt it. Also we have no choice.

How did you get involved in the non-profit Nothing but Nets?

I spent time in my childhood in Africa and had malaria as a child. My sister had a serious case of malaria in Africa. And then Rick Reilly wrote a column on the back page of Sports Illustrated. It was a simple plea talking about, “If we all gathered a buck, or two, or $10, we could buy one net, and then we could help this village in Africa.” The outpouring of money and support was, A, surprising, and B, led to the formation of this group called Nothing but Nets where the mandate was “let’s put a dent into the disease that is malaria.” Our pipeline is very simple. Ten dollars here buys one net and that net gets handed to a family, and you can track it. Nothing but Nets paired with the UN, and the thing just grew and grew. I went to Uganda. We went to refugee camps. Malaria was killing their children, and it’s incredible that you can drop a mortality rate by 80% by simply handing out nets. Our goal is to get rid of malaria. It’s a worthy cause, direct and simple.

You organized the Cavanagh Classic basketball tournament as part of that.

Yeah. The Cavanagh Classic is an obnoxiously-named charity basketball game that is furthering the cause of Nothing but Nets. So I badger some of my fancy, famous friends. I still play basketball in a couple leagues in New York City. So I say, ‘Hey, come do some good.’ We do it at the Rucker, which is one of the best-known city playgrounds. It’s in New York City. It’s a lovely event. I think the worst job at that event is the person who dresses up in the mascot uniform, which is this giant furry mosquito, and we try and hold it in the summer, and that person has to lose about 20 pounds in sweat by stuffing themselves into a mosquito costume and dancing around for the Nothing but Nets Cavanagh Classic.