Temporal engine
From Tardis Wiki, the free Doctor Who reference
Temporal engines were devices that allowed multiple different timelines to exist simontainiously. Known engines were kept in the Red Waterfall facility for Chen-7 on Apalapuchia, which allowed more than 4000 timlines to exist in seperate realities. Exhaust from the engines prevented Handbots from locating patients, such as the accidentally-admitted Amy Pond. (DW: The Girl Who Waited).
