How do I end an SP map?

[DaFatCat]

I need to know how to make an SP map for HL2 return to the main menu. (game_end only works in multiplayer) hmy:

 

[BrokenTripod]

Send a console command: "disconnect" ?

I really have no idea, though. Most SP mods and such that I've played roll credits and assume you know how to quit.

 

[A Boojum Snark]

point_clientcommand, send it the Command input with a parameter of startupmenu force