As if to help in the deception, it so happened that the Archbishop of York, who lived next door, was also giving a dinner party on that same evening - and the spies of the conspirators, being deceived by the carriages setting down the guests, reported the fact in Cato Street, adding that "all was well."
Thistlewood and his gang therefore missed their opportunity (had they known the true state of the situation) to escape, and the Bow Street officers, headed by their leader Smithers, apprehended the villains while they were arming themselves by the light of two or three candles.
The ascent to the loft was by a ladder, and as Smithers appeared at the top of it and tried to seize Thistlewood, he was stabbed through the body and killed. The lights were extinguished, and in the confusion Thistlewood and some of his companions escaped out of a back window.
However, nine of the conspirators were captured that same evening in possession of their arms, and Thistlewood himself was apprehended before eight o'clock the following morning at a house in White Street, Little Moorfields.
The whole gang was sent to the Tower; Thistlewood and four of his chief confederates were subsequently hanged, five others were transported for life, and one was pardoned.