It popped up overnight, a fully-formed three-storey hotel in the middle of The Level. Equipped with headphones that offered a "potential narrative", we were invited to gawp in through the windows at the guests moving behind the windows.

At each neon-lit glass square, odd and seemingly unrelated scenes played out - a woman taking a dip in the rooftop pool, a man dancing in his room, a maid Hoovering. They seemed stuck in a loop, repeating their motions over and over, oblivious to what was going on next door. The effect was as mesmerisingly dull as watching stacks of flickering TV screens in Currys.

It could have been bleak - an allegory for the internet age, where we make ourselves more separate while ostensibly brought closer together - were it not for the creeping sense of menace that had entered the building with a delivery man. The hotel suddenly seemed to have a visibly raised heartbeat, each room pulsating in sync with the ominous, ambient sounds coming through our headphones as the masked figure tried to deliver his glowing parcel.

Quite what was happening was impossible to guess. Was the man with an axe a killer or a naughty child? What was living in the cupboard that required a fish to be tossed in before it would give up the Hoover? An infection seemed to be spreading through the rooms.

Locked into separate worlds by our individual soundtracks and watching helplessly from outside, we suddenly seemed as trapped as the hotel inhabitants, doomed to watch without being able to affect a change. Was this a nightmarish spin on the passive nature of audiences? A warning against casual voyeurism? This chilling, dazzling spectacle simply defied explanation.