The grappling hook is an other movement tool. The primary mode attaches itself to all sorts of solid objects and will pull you there to move through the map like spider man. You can get very fast that way or reach spots you would not get to by other means. The secondary firemode drops a small gravity bomb that will affect enemy players and also releases a lot of smoke which will make you harder to see and hit. The gravity bomb uses cell ammo. There is also a mutator that adds a off-hand hook which can be used all the time, uses no ammo but only does the pulling part.

Its primary fire is the normal grappling hook. It can be used even though g_grappling_hook is disabled.
Its secondary fire looks like a mortar shell falling down. When it hits something, it explodes, generating a lot of smoke and a blue light. This is pretty much like a smoke shield, everyone close wont see anything unless they get out of the smoke. This attracts players in a quite large radius, dealing some damage. It uses 25 cells per gravity bomb, which is a lot compared to other cell-using weapons.