"Elseworlds" Synopsis Revealed, Answering Arrowverse Crossover Questions

The CW has released the official synopsis for "Elseworlds," the three-night, three-part crossover event coming to the network in early December.

The crossover loses DC's Legends of Tomorrow this year, but gains both Superman (Tyler Hoechlin) and Batwoman (Ruby Rose), as well as spending some time in Smallville and Gotham City along the way.

The heroes of the CW DC multiverse will face off with John Deegan, an Arkham scientist who almost certainly has ties to the DC villain Dr. Destiny, as well as The Monitor, who in the comics is a good guy, but who often has his own inscrutable agenda.

Each of the three shows will air in a special time slot to accommodate the "Elseworlds" storyline. The Flash, "Elseworlds, Part 1" will air on Sunday, December 9 (8:00-9:00pm ET); Arrow, "Elseworlds, Part 2," will air Monday, December 10 (8:00-9:00pm ET); and Supergirl, "Elseworlds, Part 3," will air on Tuesday, December 11 (8:00-9:00pm ET).

You can check out the official synopses below:

"Elseworlds, Part 1" — (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)

EPIC ELSEWORLDS CROSSOVER KICKS OFF TONIGHT — When Barry Allen (Grant Gustin) and Oliver Queen (guest star Stephen Amell) wake up one morning and realize they have swapped bodies with each other, the two set off to find out what disturbed the timeline to cause such a shift. However, things quickly go from bad to worse when they present their case to Team Flash and the gang doesn't believe them. Barry and Oliver realize they need Supergirl's (guest star Melissa Benoist) help and travel to Smallville on Earth-38 where they end up meeting Kara's cousin, Clark Kent (guest star Tyler Hoechlin), and intrepid reporter, Lois Lane (guest star Elizabeth Tulloch). LaMonica Garrett guest stars as The Monitor. Kevin Tancharoen directed the episode written by Eric Wallace & Sam Chalsen.

"Elseworlds, Part 2" — (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)

THE ELSEWORLDS CROSSOVER CONTINUES IN GOTHAM CITY WITH BATWOMAN (RUBY ROSE) — With Oliver (Stephen Amell) and Barry (guest star Grant Gustin) still stuck in the other's bodies, the two get a lead on John Deegan (guest star Jeremy Davies) and head to Gotham City with Supergirl (guest star Melissa Benoist) to figure out why their reality has changed. While there, they meet the mysterious Kate Kane (guest star Ruby Rose) who provides them with information that leads the group to Arkham Asylum. James Bamford directed the episode with teleplay by Marc Guggenheim and story by Caroline Dries.

"Elseworlds, Part 3" — (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)

THE BATTLE CONCLUDES — Supergirl (Melissa Benoist), The Flash (guest star Grant Gustin), Green Arrow (guest star Stephen Amell) and Superman (guest star Tyler Hoechlin) engage in the battle of their lives. Jesse Warn directed the episode with story by Marc Guggenheim and teleplay by Derek Simon & Robert Rovner.