On Monday night, Stephen Colbert made his on-air return after few days absent from the airwaves. As you might have heard, the Late Show host was in Russia, taping material for his show and popping over to Russian late-night series Evening Urgant, where he jokingly teased a presidential run. (“I thought it would be better to cut out the middleman and just tell the Russians myself.”) Colbert infused Monday’s installment of his own show with Russia-inspired jokes—and promised viewers a week’s worth of Russia content, presumably once production finishes going through hours of footage. But there’s another reason for Colbert’s trip, as well—one that, in the bigger picture, is a lot more important: he wants to remain the No. 1 host in late night, and to do so, ambition is key. After all, Colbert’s not the first late-night host to go to Russia.

“It is good to be back in the U.S.A.,” Colbert said as he opened his show Monday night. “I don’t know if you knew this, but I was in Russia last week. You know who did know I was in Russia? Russian intelligence. Hardcore fans, evidently. Followed me everywhere. Also got some attention from American intelligence. A couple guys seemed to pop up everywhere we went. But it’s important. Keep your eye on a comedian . . . I could be giving state secrets to the Russians. Oh, wait. Somebody’s already got that covered.”

Colbert also addressed his potential presidential run, quipping, “All I said in that little clip there was that I was considering a run. If I decide to run, obviously, I’m not gonna ask the Russians to help my campaign. O.K.? I’d have my son-in-law ask them.”

In total, the Late Show team shot four or five pieces in Russia, but the host didn’t specify when these remote segments might air. The trip took months of planning, Colbert said, and yielded a week’s worth of content. Perhaps not coincidentally, Emmy nomination-round voting closed Monday night—just days after Colbert made his trip public, first through a snarky tweet addressed to Donald Trump.