Please Note: This is a Half-Life Crossover, so there will be gore.... and language... and bad puns/references (Ever seen the Minds?)... Just a warning.

The timeline from the original Half-Life game is split just before the final teleportation scene. Gordon finds himself trapped in Equestria, a seemingly peaceful dimension inhabited by three separate races of sentient ponies. However, the peace is shattered when elements of both Earth and Xen begin to bleed through the second inter-dimensional rift Gordon had created. (The first being the initial resonance cascade).