Lana's Escape is a five mission campaign created by JG Finat as Hephalistofene. This is a version with a fixed download link, included AIN files. Fully compatible with the original VPK, what means that you can connect to each other or to dedicated servers with no problems.
Investigate in an IAF weapon facility.
Download
http://gamebanana.com/maps/190050
http://www.moddb.com/games/alien-swarm/addons/lanas-escape
Installation Instructions
Also run snd_updateaudiocache command in game console after installation and restart game if you want to hear custom sounds the map uses.