Prison psychologist Willis Embry reports for work at a New Jersey jail after his apartment has been burgled and his girlfriend has dumped him.

In a supposedly private meeting later, a cancer-stricken elderly convict tells Willis about a job he pulled many years earlier: stealing $8.5 million of Mafia money, hidden in a casino skim bank.

In the next cell, inmates Lyle and Handsome Harry listen in to the conversation, but fail to hear the house number correctly, putting down 7320 instead.

Their sociopathic accomplice Marvin has rigged Embry's apartment to explode, but he manages to escape the explosion, although the police think he died.

The following morning, Lyle, Harry, and Marvin arrive at 7320 and take the homeowners, Norman and Peedi Rutledge, hostage, while they start to dig in the basement.

Meanwhile, Willis arrives next door at number 7322 and poses as a furnace engineer to get inside Jessie Lodge's house and scout the basement for the digging spot.

After a failed attempt at taking the house by force, Norman suggests that their existing hole be turned into a tunnel to next door, while Jessie and Willis continue digging.

Later, as they sit in the hole in the basement and realize their true love for each other, Willis and Jessie notice a large bag of hidden gold coins.