Monday night’s episode of Jeopardy! had an unexpectedly moving Final Jeopardy round as contestant Dhruv Guar used his answer to wish host Alex Trebek well. The clue was “In the title of a groundbreaking exposé of poverty in New York City slums, these three words follow ‘How the,’ ” and the answer-in-the-form-of-a-question Trebek was looking for was, “What is ‘Other Half Lives?’ ” Here’s the answer-in-the-form-of-a-question Guar offered instead, which got Trebek choked up:

Trebek, 79, has Stage 4 pancreatic cancer, a diagnosis he announced in a video message this March in his typical dry fashion:

Emma Boettcher, the contestant who ended James Holzhauer’s winning streak earlier in the summer, got the highest score and will be advancing to the next round of the Tournament of Champions, but it’d be hard to argue Guar wasn’t the winner here. After the episode aired, Guar explained in a Twitter thread that Trebek had just told the contestants he was going to be undergoing more chemotherapy to treat his cancer:

Jeopardy! fans have been tweeting support for Trebek using the hashtag #weloveyoualex. Meanwhile, the contestants in this year’s Tournament of Champions are raising money for the Lustgarten Foundation for pancreatic cancer research, in honor of Trebek and Larry Martin, who won last year’s Jeopardy! Teachers Tournament shortly before dying from pancreatic cancer.

The tournament’s contestants are also encouraging home viewers to play along with the show this Thursday and Friday, then donate $1 for each correct answer. Trebek has hosted Jeopardy! since it was relaunched in 1984.