‘Grove left the theatre with Miss Meade and her party saying he would go to Canonbury and pick up his guitar. He had in fact brought his guitar to the theatre and had hidden it in a broom cupboard in the property room where it was found in the course of his illicit explorations, by Trevor. Grove got into his open sports car, drove round the block and parked the car in Phipps Passage. He re-entered the theatre by the pass-door while Mr Morris and Mr Knight were in the office. He may have been seen by Jobbins who would think nothing of it as Grove was in the habit of coming round for messages. He was not seen by Miss Bracey who mistook Jobbins for him because of the coat.

‘Grove remained hidden throughout the rumpus about Trevor until, as he thought, the theatre was deserted except for Jobbins. At eleven o’clock he dialled his own number and let it ring just long enough for his wakeful neighbour to hear it and suppose it had been answered.

‘It must have given him a shock when he heard Trevor, in the course of his fooling, pluck the guitar string. It was that scrap of evidence, by the way, when you remembered it, Jay, that set me wondering if Grove had left his instrument in the theatre and not gone to Canonbury. A moment later he heard the stage-door slam and thought, as Mr Jay and Miss Dunne and Jobbins did, that Trevor had gone. But Trevor had sneaked back and was himself hiding and dodging about the auditorium. He saw Miss Bracey during his activities. Later, he tells us, he caught sight of Harry Grove and began to stalk him like one of his comic-strip heroes. We have the odd picture of Grove stealing to the broom-cupboard to collect his guitar, flitting like a shadow down a side passage, leaving the instrument ready to hand near the front foyer. Inadvertently, perhaps, causing it to emit that twanging sound.’

Peregrine gave a short ejaculation but when Alleyn looked at him said: ‘No. Go on. Go on.’

‘Having dumped the guitar Grove returns to the stairway from the stage to the circle, climbs it and waits for midnight in the upper box. And, throughout this performance, Trevor peeps, follows, listens, spies.

‘At midnight Jobbins leaves his post under the treasure and goes downstairs to ring Police and Fire. Grove darts to the wall panel, opens it, uses his torch and manipulates the combination. There had been a lot of talk about the lock after the safe was installed and before the treasure was put into it. At that time it was not guarded and I think he may have done a bit of experimenting, after hours, on the possible “glove” combination.’

Winter Morris knocked on his forehead and groaned. Marcus Knight said: ‘Oh God!’