Paradox Shield
From Tardis Wiki, the free Doctor Who reference
A Paradox Shield was a device created by the War Doctor to prevent Marinus from being attacked by the Daleks during the Last Great Time War. (COMIC: Four Doctors)
A Paradox Shield protected Lara Zannis, a human agent of the Daleks who invaded Earth and exterminated humanity in 1961. Once the shield was broken, Lara was banished to this alternate timeline when the War Doctor restored the course of history. (AUDIO: The Shadow Vortex)
