闪电在第一季结束回到过去的时候意外的打开了穿越之门，制作团队妥善利用多元宇宙介绍新反派是怎么挑战闪电团队的，包括最最坏的，不可击败的极速

　　地球2因为二重身被我们所熟知，很多熟悉的角色都和地球一走上了不一样的路，巴里没有成为闪电，并且和艾瑞斯结婚了，同时凯特琳和罗尼黑化，成为了冰霜杀手和死亡风暴，现在粉丝会在交叉集能看到二重身。

　　绿箭的黑金丝雀已经被我们所熟知，特别是西斯科，他帮着造了那个声呐武器，巴里和他的伙伴会看到一个全新版本的她，绿箭的制片人确认Cassidy 会在地球二出演Black Siren.

　　The Flash has made the most of that gateway to Earth-2 that Barry (Grant Gustin) accidentally opened when he dabbled in time travel at the end of season 1. The series has used the alternate world to introduce a host of new villains to challenge Team Flash, including the biggest bad guy of all, the seemingly undefeatable Zoom.

　　Earth-2 also introduced the doppelgangers of characters we already know, many of whom have taken a different path than their Earth-1 counterparts. Barry never became The Flash, and he married Iris (Candice Patton). Meanwhile, Caitlin (Danielle Panabaker) and Ronnie (Robbie Amell) went to the dark side, transforming into Killer Frost and Deathstorm. Now fans will be treated to a doppelganger that’s only interacted with Team Flash on crossover events.

　　While Arrow’s Black Canary (Katie Cassidy) is well-known, especially to Cisco (Carlos Valdes), who created her signature sonic weapon the Canary Cry, Barry and his friends will soon encounter a whole new version of her. Arrow executive producer Marc Guggenheim has confirmed, via TVLine, that Cassidy will appear on The Flash as Earth-2’s version of Laurel, Black Siren.

（编辑：何莹莹）