Call The Doctor
The plot is that some undetected zeroday flaw in the LHC control system allows interdimensional hackers to take over the collider and synchronize the collisions so that they intersect with their dimension and allow an invasion to take place.
The Doctor turns up at the crucial moment and throws a sonic spanner in the works, causing the interdimensional aliens to get sent hurtling back into their domain with a polite note not to bother humanity again "Or Else!"
Cue lots of LHe ownage and assorted Sheldon-like boffinry running around screaming because the aliens "Know about superstring particle fluxion theory".
Hint: Amy Pond nearly gets frozen but is rescued at the last second, yet again.