Please give a summary of "The Destructors."

This story is set in post-war London which has been ravaged by
the German bombing. T., also known as Trevor, takes the leadership of the Wormsley Common gang
away from Blackie when he suggests the organised destruction of a historic house that survived
the German blitz. While the house's owner, Mr. Thomas, who the gang somewhat cruelly calls "Old
Misery," is away, the gang thoroughly demolishes the inside of the house. When the owner returns
unexpectedly early, they lock him in his outhouse. During the night, the gang weakens the
foundations of the house and attach them to a truck that is parked close to the house, so that,
when the driver leaves the following morning, he unknowingly completes the act of destruction
that the boys have started. The driver, bemused by what has happened, releases Mr. Thomas from
the outhouse. Mr. Thomas is completely devastated by what has happened, but the driver only
laughs at the situation.