The CW's annual DC superheroes crossover extravaganza is going to be especially exciting this year, as it finally introduces Ruby Rose as Kate Kane, aka Batwoman, and features tentpole heroes Oliver Queen (Stephen Amell) and Barry Allen (Grant Gustin) trading suits.

Titled "Elseworlds," the three-part event will bring together the worlds of The Flash, Arrow and Supergirl as the heroes take on mad Arkham Asylum doc John Deegan (Jeremy Davies) and The Monitor (LaMonica Garrett), among others.

In addition to familiar characters like Supergirl (Melissa Benoist), Superman (Tyler Hoechlin), and even John Wesley Shipp as either Henry Allen or Jay Garrick, we can also expect to see the introduction of some new faces, like Lois Lane (Elizabeth Tulloch) and Nora Fries, aka Mrs. Freeze (Cassandra Jean Amell).

Thanks to all of the apparent reality-bending hijinks afoot, the many unknowns about what our friends will face, and at least one emotional Smallville tribute, "Elseworlds" promises to be an absolute event for the small screen.

So, make room on your calendar for these dates and showtimes, all airing on The CW.

Sunday, Dec. 9: The Flash at 8/7c
Monday, Dec. 10: Arrow at 8/7c
Tuesday, Dec. 11: Supergirl at 8/7c

The episodes can also be streamed the next day on CWTV.com. You can also watch on fuboTV — start a free trial today!

(Disclosure: TV Guide is owned by CBS, one of the CW's parent companies.)