Headcrab Infestation

"Headcrab Infestation" (also known as Half-Life Christmas Special 2: Headcrab Infestation) is the first City 17 Street Christmas Special and well as the second Christmas Special for Half-Life.

The episode is currently lost, with plot details (apart from a small synopsis) gone.

Plot
A cargo of headcrabs escape from Combine hands and are unleashed into City 17 on Christmas Eve.

Reboot
The story was rebooted in 2021 (fifteen years after the original special) as part of the "City 17 Christmas Hits" which saw past Christmas Specials being partially remade. The story depicts a Headcrab outbreak across City 17, with Father Grigori being drafted in by the Combine in order to help out their clean up crew and make sure City 17 has a decent Christmas. When the situation becomes too overwhelming Grigori hides away in a cellar by the trainstation, where he comes across a mural of Gordon Freeman (who has yet to arrive in City 17). Grigori becomes hopeful this individual will give them salvation, and comes to realise they will celebrate the zombie invasion. The zombies are cleaned up by the next morning, with Wallace Breen wishing the citizens a good Christmas.

Development
The story was originally devised as a spin-off holiday special to Half-Life 2: Episode Four.