Adding on to secure, undisclosed location? Bunker-buster tests? Cheney's dinner didn't agree with him? Secret explosions occuring at the Veep from the Deep's mansion. The Post said neighbors have several theories about what the project might involve. One is that the government is building a security bunker for Cheney. Another is that it is digging tunnels to spy on nearby embassies. Still another is that a helicopter hangar is being built.