Quantum shield
From Tardis Wiki, the free Doctor Who reference
Quantum shield was a defence force field which the Time Lords placed around their allies. The Earth was one such planet. In 1961, under the command of the Dalek Time Strategist, Lara Zannis breached the barrier and Cardinal Ollistra sent the War Doctor to trace her before the Daleks attacked Earth. (AUDIO: The Shadow Vortex)
