Since nothing did get organised for last night, I spent it building a mighty construction of mechanical and hydrodynamical genius in Dwarf Fortress. It's a water powered spike trap. Goblin walks into a room. The doors seal behind it and a series of spikes start stabbing up out of the floor in a checkboard pattern. Poor sods won't stand a chance as I doubt the AI is clever enough to realise there is a pattern to which spikes are popping up next. Plus of it's not 100% accurate at alternating between the two different groups of spikes.
Of course it's probably all a waste of time as the stupid dwarves have some how managed to exhaust their winter supplies and haven't managed to replenish them quickly enough yet. So I'll expect them all to have died of starvation long before another attack arrives.