Fragson's engagement at the Royalty was in the two act comic opera Castles in Spain, with music by himself, the libretto by Cosmo Hamilton (based on La Gran Via), and lyrics by Eustace Pnsonby. The piece, directed by Gaston Mayer, opened on 18 April 1906. It transferred to Terry's Theatre on 24 May 1906 to score an eventual run of 68 performances. Other members of the cast included Johnny Danvers, Edouard Espinosa, May de Sousa and Kitty Lindley. Besides several more music hall appearances in London, Fragson was in two further Drury Lane pantomimes: Sinbad in 1906, and Babes in the Wood in 1907.

Paris, December, 1904.
'The weather was bad and I handed two francs to the cabman, although his taxametric machine would probably, I thought, claim considerably less (writes our Paris Correspondent). Then the cabman turn round and spoke. He spoke long, flowingly, and with considerable vigour. I don't remember ever to have heard quite such vituperation, excepting from the lips of Kent before they put him in the stocks in William Shakspere's domestic tragedy, King Lear. The taxameter, which was abnormally large, claimed forty-seven twenty-five for a six minutes' drive, and, as the crowd grew, so did the flow of language from the cabman. Then he called up a colleague and explained to him, and suddenly invited my friend and myself to get back into the cab again and to be driven up for justice. On the way there, Herbert Ward, a sculptor, who was a member of Stanley's celebrated Rearguard at Yambuya, a man who has shot elephants, hunted the winsome tiger, and indulged in various other dangerous pursuits, remarked that tiger-hunting was not in it for real danger with a drive behind a cabby like the one we had, and I began to feel that he was right. The cab stopped. Jehu clambered off his box, pointed and said, "C'est là," and in we went.
'The place was more like a studio than a police-station, and, when a big man with a heavy moustache and a strong resemblance to our cabman came in and shook hands affectionately with an articulated skeleton sitting on a chair by the door, we began to smell a rat. His clothes were brick-red, save the waistcoat, which was scarlet. His tie was of a pale green, and Ward suddenly exclaimed, "Why, that is Monsieur Philibert from the Revue now going on at Parisiana!" "And Philibert is Fragson!" shouted I. "And Fragson was the cabman," Monsieur Philbert remarked, in English, " and I am Harry Fragson, at your service." But, even after we had found him out, Fragson would not stop working. His face and costumes changed with biographic suddenness; he insisted on introducing Ward, the traveller, to a young family of his from Africa, and when we, in the course of conversation, mentioned Abel Faivre, Fragson became the painter's well-known figure of a concierge in about three minuets. "And do you think that I shall get on in London?" was his parting question. "I am awfully afraid about it, because, although I am an Englishman, and a Cockney at that, I've never faced a London audience." "I don't see what you've got to be afraid of," we both said together. "Paris audiences are critical enough, and you are pretty popular in Paris. What do you fear from London?" Harry Fregoli-Fragson [Fregoli: a contemporary quick change performer] was in dress clothes by that time, and at the piano, "C'est le flegme, le grand flegme, le grand flegme Bitannique," he chirruped merrily, and gave us rendezvous at Drury Lane next winder as we went.'
(The Sketch, London, Wednesday, 21 December 1904, p.336)

Fragson was shot and mortally wounded by his deranged 83 year old father, Victor Potts, at their apartment in the Rue Lafayette in Paris about 9 o'clock on the evening of 30 December 1913. He was dead on arrival at hospital. Potts himself died shortly afterwards in a state of mental collapse in the Fresnes Prison, Paris, on 17 February 1914
(The Times, London, Tuesday, 17 February 1914, p.5a, and Wednesday, 18 February 1914, p.8d)