Warning: this review contains full spoilers for The Flash: Season 6, Episode 5! If you need a refresher on where we left off, here’s our review for Season 6, Episode 4.
The Flash would definitely have viewers believe Barry Allen won’t make it out of Crisis on Infinite Earths alive. That outcome seems unlikely, especially without a potential replacement speedster waiting in the wings, but stranger things have happened in the Arrowverse. And whether or not Barry is doomed to die in two months, “Kiss Kiss Breach Breach” serves as a test case. Can The Flash function without its lead hero? As it turns out, the answer is “potentially.”
Source: IGN.com The Flash Proves It Doesn't Always Need Barry Allen.