Step in the wrong spot, and the wall smashes you. Well, not really; it stabs its spikes into you. And these spikes are covered in medium monstrous spider venom.
Detect: Per-based Traps at -2.
Disarm: DX-based Traps at -2.
Circumvent: DX or Jumping at -2.
Evade: Dodge at -2.
Effects: 3d+1 impaling plus poison to two targets in 3 hexes; resist HT at +1 for the poison or lose 1d-3 ST; resist HT at +1 again a minute later or lose another 1d-3 ST.
Rearm: Yes, but the poison has worn off.