Cisco, Caitlin, and Wells are in the Cortex. When the ground starts to suddenly shake, growing in magnitude by the second.

Cisco: The hell-?

The frequency tracker (Which is pretty much for high scale anomalies) starts making violent pings.

Caitlin: Something is screwing up the accelerator ring stabilization.

She looks over at Wells with a concerned expression

Wells: Something is wrong. Call back Barry. Now!

Cisco(Over comms): Barry! Get back to Star labs pronto!

Barry: On it!