The Flash episode The Trap referenced Green Arrow, Hawkgirl, and The Atom.
A potentially fun crossover is too little substance and too much of a stalling tactic for the real meat of the story.
Screen captures from the extended promo trailer for the Flash episode All-Star Team Up
Preview clip for the Flash episode All-Star Team Up
Screen captures from a preview clip for the Flash episode All-Star Team Up
CW video with Andrew Kreisberg taking fans inside the Flash episode All-Star Team Up
Canadian promo trailer for the Flash episode All-Star Team Up with callbacks to Brandon Routh's other famous role
Extended promotional trailer for the next new episode of The Flash on The CW, titled All-Star Team Up
Preview images for the Flash episode All-Star Team-Up, guest starring Emily Bett Rickards and Brandon Routh from Arrow
Official CW description for the Flash episode All-Star Team-Up featuring Brandon Routh and Emily Bett Rickards from Arrow