Crisis on Infinite Earths Continues on Arrow and Legends of Tomorrow

Special events dominate today's lineup, with Crisis on Infinite Earths returning from holiday break, Jeopardy: Greatest of All Time turning into an all out battle of the brains, Democrats taking the debate stage one more time before the pivotal Iowa Caucuses, and Leslie Jones debuting her new comedy special. Here's what's new and noteworthy on TV this Tuesday:

CROSSOVER EVENT: After taking a month-long break for the holidays, the crossover event Crisis on Infinite Earths concludes with back to back episodes of Arrow and Legends of Tomorrow. When we last left off, the earth(s) had been destroyed, with only our heroes (and one Lex Luther) left, relegated to the Vanishing Point.  The million dollar question is will the cataclysmic events of this crossover have any lasting impact on the shows involved? No spoilers, but as Primetimer's Josh Zyber speculates, the mostly likely answer is no. 8:00 PM ET on The CW

SPECIAL EVENT: Last week's three night special event has turned into an all out "dog fight" between Ken Jennings and James Holzhauer, causing Jeopardy: Greatest of All Time to return for a fourth installment tonight. With the title going to the first returning champ to win three games, Jennings needs just one more victory to bring competition to a close, but if Holzhauer can clinch his second win, or Brad Rutter can get his first, the competition will continue tomorrow night, which should be just fine with ABC as ratings have exceeded all expectations. 8:00 PM ET on ABC

LIVE DEBATE: Bernie Sanders and Joe Biden are set to take center stage at Drake University for the final Democratic Presidential Debate before the Iowa caucuses. Joining them will be Elizabeth Warren, Pete Buttigieg, Amy Klobuchar and Tom Steyer. CNN's Wolf Blitzer and Abby Phillip, as well as The Des Moines Register's Brianne Pfannenstiel, will moderate 9:00 PM ET on CNN

COMEDY SPECIAL: In her first Netflix comedy special Leslie Jones: Time Machine, the SNL alum tackles sleep apnea, the evolution of her prayers, and her romantic pursuit of The Purple One. Watch the trailer. Streaming on Netflix

NEW EPISODE: The return of This is Us finds Kevin (Justin Hartley) looking to make an emotional connection, while Kate (Chrissy Metz) meets Toby's CrossFit buddy. Watch the preview. 9:00 PM ET on NBC

ALSO TONIGHT

• Ellen's Game of Games airs an episode entitled "Hit Me Baby One More Slime," featuring... you guessed it: slime. 8:00 PM ET on NBC
• New Amsterdam jumps into lockdown when a prisoner goes missing while undergoing treatment. 10:00 PM ET on NBC

Mike Attebery is Senior Editor at Primetimer and the author of seven mystery thrillers. Follow him on Twitter at @mikeattebery.