Released a couple of years ago on Hotline, finally being added to the Archives. A pretty straightforward multi-room map, with a bunch of teleporters to move you around if you don't like taking the long way. Only real problem is that the teleporter pads are quite small... hard to hit 'em right if you're being shot at. (Maybe that was the intention, actually.) One of the rooms is shaped like a baseball diamond, hence the name. Them TI textures are purty!