Can't plan this.

When Marty and Leeane had their housewarming Tim brought a little gift along on the night. The gift was a count down timer connected to a very, very loud siren.
The plan was to activate the timer just before we left - the timer would start its countdown and activate the siren after two hours. The siren, placed in a cardboard box, was left in a spare room, easily spotted when the time came to stop the noise.
It was harmless fun - what could go wrong?

I actually forgot about the whole thing when I woke the next day, but Tim rang me giggling hysterically. This is what actually happened...

We left at 2:20am, so the siren went off at about 4:30am. The problem was that Marty was so hammered he didn't wake up first; his wife Leeane did. Thinking someone had activated the house security system she keyed in the 4 digit pin code, but by doing this, she actually activated the house security system. Sixty second later the house system triggered and it's siren went off as well. So now two sirens were blaring, and our 30 second prank had just woken all the neighbours.
Convinced that she had put in the wrong pin code for the alarm, Leeane started entering numbers from their previous house's alarm system. After 6 incorrect pin numbers the alarm locked on refusing to accept any more attempts.
At this stage Leeane ran down to the master bedroom and managed to shake an inebriated Marty to life. Of course we didn't realise Marty slept in the nude, but those who slept over that night got an eye-full as he bounded naked down the hall toward the security panel. Realising he was too drunk to follow the complex reprogramming sequence to reset the locked alarm, Marty ripped the security panel off the wall pulling out every cable he could find.
The internal house siren silenced (but not our one), Marty rushed toward the balcony to silence the outside siren. At the last minute Leeane yelled at him to put on her dressing gown, and all the neighbours watched in amusement as Marty stood on his balcony in his wifes favourite pink satin dressing gown, hitting the hell out of the external alarm box with a hammer. Eventually the siren could take no more and plummeted to the ground, one story below, screaming no longer.
It was then, and only then, that Marty heard the siren in the spare room. He opened the cardboard box, pulled off the battery wire, and finally there was silence.

Marty, God bless him, saw the funny side of it all afterward. He even admitted the whole incident broke the ice with all the surrounding neighbours. I'd love to take credit for it all, but I was only guilty by association. Tim retired from housewarming pranks that night; undefeated, at the top of his game - the best way to go.

Actually, come to think of it...I wonder if Tim still still has the answerphone messages made between 4:30 and 4:45am that night. I'm sure any statutes of limitations are long past. If they're about I'll link to them. Please forgive me, but the memory of those messages still make me smile.