Fail-safe

From Tardis Wiki, the free Doctor Who reference
Fail-safe

In the middle of 2019, The Thirteenth Doctor built in a fail-safe to the Silver Lady after tracing its movement through history. (TV: Spyfall)

The Doctor's TARDIS had a fail-safe which if it was suffering impending breakup of its dimensions it locked onto the nearest spacecraft. (TV: Terminus [+]Loading...["Terminus (TV story)"])