Elseworlds (Arrowverse)

Lore & Background

The crossover was confirmed in May 2018 at The CW's upfront presentation, where the inclusion of Batwoman and Gotham City were revealed. Casting throughout August and September 2018 included Ruby Rose as Batwoman, Elizabeth Tulloch as Lois Lane, and the announcement that Tyler Hoechlin would return as Superman. The title 'Elseworlds' was announced at the end of September, and filming began in October 2018. In the crossover, Arrowverse actors portray other roles, and John Wesley Shipp reprises his role as Barry Allen / Flash from the 1990 series The Flash. The conclusion of 'Elseworlds' set up 'Crisis on Infinite Earths' as the next crossover, which aired between December 2019 and January 2020.

The plot involves a mysterious figure, the Monitor, giving the Book of Destiny to Arkham Asylum psychiatrist John Deegan. Deegan uses the book to rewrite reality, temporarily corrupting the real Superman from Earth-1 into a black-suited version of himself.

Reader's Guide

Elseworlds is significant as the fifth Arrowverse crossover and a key narrative bridge, introducing Batwoman and Gotham City to the shared universe, which later led to a standalone Batwoman series. It also marked the first appearance of Lois Lane in the Arrowverse. The crossover's title references DC Comics' Elseworlds imprint, which features stories outside mainstream canon. The event was produced without Legends of Tomorrow due to capacity and tonal concerns, and its conclusion directly set up the massive 'Crisis on Infinite Earths' crossover the following year. The crossover demonstrated the Arrowverse's ability to adapt classic DC storylines and expand its roster of characters, while also experimenting with role-swapping and alternate realities. Its legacy includes establishing Batwoman as a major figure and deepening the interconnectedness of the Arrowverse's Earths.

The Three-Night Narrative Architecture

Elseworlds unfolds across three consecutive nights in December 2018, each anchored to a different CW series: The Flash opens on December 9, Arrow follows on the 10th, and Supergirl closes the event on the 11th. The central conceit revolves around the Book of Destiny, a reality-rewriting artifact in the hands of Arkham Asylum psychiatrist John Deegan, who uses it to swap the lives and powers of Oliver Queen and Barry Allen. This forced exchange sends Barry into a world where he is disbelieved and locked in S.T.A.R. Labs, while Oliver must navigate a life without his archery skills. The heroes eventually travel to Earth-38 to recruit Kara Danvers and Clark Kent. The story escalates through a mass breakout at Arkham, a fear-gas hallucination sequence in which Barry and Oliver mistake each other for their respective archenemies, and a rewritten reality where the two become powerless criminals branded the Trigger Twins, hunted by a black-suited Superman who is actually Deegan in disguise. The climax sees Barry and Kara slowing time by speeding in opposite directions around the globe while Oliver negotiates with the cosmic entity Mar Novu, ultimately allowing an arrow to shatter the book and restore the status quo.

Expanding the Arrowverse Universe

Beyond its three-episode plot, Elseworlds functions as a major expansion point for the shared Arrowverse. The event introduces Batwoman, portrayed by Ruby Rose, as Kate Kane, the CEO of Wayne Enterprises operating out of Gotham City. It also brings Lois Lane, played by Elizabeth Tulloch, into the narrative alongside Tyler Hoechlin's return as Superman. Gotham City itself debuts as a new location within the Arrowverse, though it is explicitly distinct from Fox's separate Gotham television series. The crossover also introduces the cosmic entity Mar Novu, who is testing worlds for an impending crisis, and the android A.M.A.Z.O., which awakens to threaten Central City. The mysterious figure who appears at the conclusion—telling Deegan that "worlds will live, worlds will die, and the universe will never be the same"—plants the seed for a far larger multiverse threat. Additionally, John Wesley Shipp reprises his role as Barry Allen from the 1990s live-action Flash series, bridging decades of television history within the same shared narrative.

Production Decisions and Casting Timeline

The path to Elseworlds was shaped by exhaustion and negotiation. Following the previous year's four-series crossover Crisis on Earth-X, executive producer Marc Guggenheim acknowledged that the production crews were "pretty burned out," still feeling the strain a full year later. The producers initially wanted to skip a crossover entirely, but The CW persuaded them to proceed on the condition that it would not involve all four series simultaneously. The project was officially confirmed at The CW's May 2018 upfront presentation, where Mark Pedowitz and Stephen Amell revealed the inclusion of Batwoman and Gotham City. Casting announcements rolled out through August and September 2018, with Ruby Rose cast as Batwoman, Elizabeth Tulloch as Lois Lane, and Tyler Hoechlin's return as Superman confirmed. The title was revealed at the end of September, and filming commenced in October 2018. Notably, several credited cast members did not actually appear in their respective episodes, reflecting the logistical complexity of coordinating three shows' rosters for a single event.

Setting the Stage for Crisis on Infinite Earths

The final moments of Elseworlds are deliberately designed as a bridge to the next major event. After reality is restored and Deegan is incarcerated at Arkham Asylum, a mysterious figure—previously seen on the destroyed Earth-90—approaches him with the ominous declaration that "worlds will live, worlds will die, and the universe will never be the same." This figure is connected to Mar Novu, the cosmic entity who had been testing worlds throughout the crossover. Novu's warning to the heroes that something is coming and they will not be able to stop it frames the entire event as a prelude. The conclusion of Elseworlds directly set up Crisis on Infinite Earths, the subsequent crossover that aired between December 2019 and January 2020. The introduction of Earth-90, the Book of Destiny, and the multiverse-testing concept all established the thematic and narrative infrastructure for that larger story. Even the personal stakes—Clark and Lois expecting a child and preparing to return to Argo City—serve to reposition characters for the events to come.