Hancock and Sid are members of a jury in the trial of a man - John Harrison Peabody - accused of stealing some jewellery. Hancock has been elected jury foreman and continually interrupts the proceedings. He asks if the jury can see the evidence for a second time, to which the judge agrees. Hancock tries on one of the exhibits - a diamond ring - but is unable to remove it. Numerous attempts to remove the ring prove futile, so he and the other jury members have to retire for their deliberations with the ring still stuck on Hancock's finger. In the jury room, Hancock finds he is the only jury member voting for a not guilty verdict, the other members being keen to bring the case to a conclusion as quickly as possible. Sid is also in favour of finding the accused guilty, before changing his mind when Hancock mentions that the jurors are being paid 30 shillings a day for their services. By using appeals to sentiment, emotional blackmail and talk of the fine tradition of British justice Hancock gradually manages to persuade all the other jurors to change their minds in favour of a not guilty verdict. One of the last jurors to be persuaded only reluctantly follows the consensus, and in doing so warns Hancock that the freed man - if he is actually guilty - might once again embark on a life of burgling houses, possibly including Hancock's. The juror's words give Hancock second thoughts, and he has an abrupt change of opinion in favour of finding the accused guilty. The rest of the jury immediately do likewise and they leave to deliver their verdict to the court, reflecting on how the values of British justice have triumphed. Back in the courtroom, Hancock announces the jury's verdict. As they are about to leave, the judge reminds Hancock that he has still not returned the diamond ring that was stuck on his finger. Hancock realises he has lost the ring, possibly when he shook hands with the other jurors. The episode ends with all twelve jury members appearing in the dock accused of theft, with Hancock - still acting as spokesperson for the ex-jurors - pleading guilty on behalf of all of them.
The comedian Ben Miller, in the BBC documentary My Hero: Ben Miller on Tony Hancock, said that "Twelve Angry Men" was his favourite Hancock episode and claimed to have watched it at least thirty times. The episode was remade for ITV in 1996 with Paul Merton in the Hancock role, as part of the series Paul Merton in Galton and Simpson's...
