Deep within the mountains, this complex has been left to ruin after whatever conflict it was involved in resolved. Bought by Mann Co, the site is being demolished to make room for warehouses. However, a sudden robot invasion has halted construction. Derelict features the following missions: Rust Removal (Normal) Intruder Exclusion (Intermediate) Torrential Downpour (Advanced1) Heavy Rain (Advanced2) Drenching Desolation (Expert, by Nuke) Cipher Chaos (Survival, by BlazingDiancie).