Its very, very faithful to the comics.
I think its massively different, he says of the four-way team-up.
The first crossover we did was two separate storylines that had a slight tangential connection to each other.

Credit: Katie Yu/The CW; Cate Cameron/The CW; Dean Buscher/The CW; Darren Michaels/Warner Bros.
This year, Guggenheim continues, were doing by far the most ambitious crossover weve ever done.
Its basically a huge three-part story that also brings in Supergirl, so its crossing over all four shows.
Its telling one big epic movie of a story.
Its not setting up any other spin-offs, its just big, bombastic, huge action.
Theres also some really poignant character moments.
Its by far the most ambitious thing weve ever attempted.
TheFlash-Arrow-Supergirl-Legends of Tomorrowcrossover is expected to kick off in November.
Tune in to SiriusXMs Ch.
105 on Thursdays at 11 a.m. PT/2 p.m.
ET for more on The CWs super series onSuperhero Insider, hosted byKyle Andersonandthis reporter.