This descending path backtracks but does eventually lead to the "N" mark. It's floating on top of a spotlight that's pointing down to another nest of the spiky Akrid. Continue ahead and you'll fall into a hole that puts you back in the hallway from before. Make your way back to the room where you got this VS (with the three exits) and we'll pick things up there. Now, with all the targets hit and a (hopefully) charged energy meter, it's time for the boss. You desperately need a VS for this battle - one is provided, but consider backtracking for an extra one.
It's a big four-legged bug. That's it. You've got ample ammo reserves and a spare VS to boot. This boss, compared to the past two, is nothing. Break two legs and it'll drop, exposing its glowing-weak-point head. You know what to do. The bug'll drop smaller Akrid every now and then, but as long as you keep moving they're not much trouble. Stick to rockets and VS shotgun blasts, but there's a grenade launcher here too.
