The CIA safe house is extremely well-prepared, and the quickest way to restore communication with the outside world is to return to the safe house.
But here's the problem: the CIA safe house must have already been under surveillance by the Japanese since Gao Yi and his team moved in, inevitably exposed from the start, although it might have been exposed long ago, and neither the Japanese nor the Americans paid much attention.
Just because there was no problem before doesn't mean there's no problem now.
Previously, there was no issue because the CIA safe house posed little threat to the Japanese. Even if there was a threat, the Japanese didn't dare intervene.
But now it's different. Now that Gao Yi has caused a nuclear explosion, the Japanese must do something, so returning to the safe house might encounter attacks from the Japanese, but staying outside makes it impossible to communicate with the external world, hindering the next steps.
