A bang came from the window of a cell on the upper floor. It sounded like a knock to the seal that persisted for some time and was loud enough to catch the attention of Andrew Mlangeni as he went through his regular morning ‘oefening’ outside. He fixed his eyes high up but didn't see anything or anyone. He decided to walk again past the place where he had heard the sound, and looked up again. This time he saw a small piece of paper being released from the window, probably the one from which the attention was sought. As it flew down to the surface like a butterfly, the warder who was supervising his exercise picked it up and he never saw its contents, nor knew, at the time, who was trying to send it to him. He was then hurriedly taken back to his cell.

A day or two later, in his cell, Andrew climbed onto his toilet bucket to peep through his cell's tiny window and saw a white man being led to exercise in the white section of the prison. It was Ben Turok who, like many other members of the SACP, had joined MK. He had evaded arrest during the 1960 state of emergency, and gone underground. Andrew had not seen him since he came back from China but had been briefed about his fate.

Andrew had learned the trick of communicating messages since the intercepted piece of paper from the upper cell window. He picked up a piece of paper and wrote the message ‘Percy is here’, confident that his code name had circulated among the leadership of MK. He banged on his window to gain Turok's attention and threw down the note, then watched with frustration as the warder guarding Turok picked it up and quickly rushed Turok back to his cell. Within a minute, the warder was in Andrew's cell, questioning him about the name Percy. Andrew insisted on his real name and denied any knowledge of Percy. Furious, the warder left with the piece of paper. Andrew did not read much into his sight of Turok because he knew the man had been convicted in 1962 under the Explosives Act and sentenced to three years in prison. Unlike Andrew and Motsoaledi, he was therefore a convicted prisoner.