I own a weaponized Roomba for home defense, since that’s what the founding fathers intended. Four ruffians break into my house. ‘What the devil?’ As I grab my powdered wig and activate my autonomous sentry unit.

It bumps into the first man. Click-clack. The mounted 1911 fires a .45 ACP round, dropping him instantly. ‘Good lord!’ cries the second, but the Roomba pivots, its optical sensors locking on. It unleashes a suppressed burst from the top-mounted M4 carbine, shredding his lace cuffs.

The remaining two try to flee up the stairs, but they trigger the tripwire. The Claymore mine strapped to the dustbin detonates with a deafening roar, sending shrapnel through the foyer wallpaper. The last survivor, trembling in the corner, thinks he’s safe until he hears the whirring. The downstairs Roomba engages its miniature, high-torque chainsaw. It drags itself toward him, cleaning up the mess as it goes.