Having no friendly Arabs to depend upon, Warren had to resort to the expedient of suddenly swooping down on some Bedouins about Zagazig, who had been fighting against us a week before, and capturing several hundreds of them. These he sorted out, imprisoning some as hostages, and taking 220, selected from various tribes, with him as an escort into the desert. He was accompanied by Lieutenants Burton and Haynes and Quartermaster-Sergeant Kennedy, all of the Royal Engineers. After ascertaining that Professor Palmer had been murdered, the expedition entered the desert in search of the murderers; Warren made his arrangements for their capture, and succeeded in taking eight out of fifteen. These were brought to trial, convicted, and hanged. During his hazardous operations Warren visited Akaba, where Arabi’s flag was flying, and reduced it to submission. He also captured Nakhl in the desert, which he reduced by surrounding it and cutting off supplies; this caused a mutiny in the garrison and they capitulated. In the House of Commons on 16th November Mr. Gladstone said that ‘Colonel Warren had performed the task of investigating the circumstances of the murders with great energy and judgment, as well as knowledge.’ On 27th November Admiral Sir Beauchamp Seymour conveyed to Warren by letter his entire approbation of the means he had adopted ‘at much personal danger to ascertain the fate of Professor Palmer and his comrades. The perseverance and zeal,’ he says, ‘manifested by you and by the subaltern officers of the Royal Engineers under your orders, more especially during the trying march between Nakhl and the Suez Canal, reflect the greatest credit on the noble Corps to which you belong.’ An Admiralty letter of 4th December 1882 to Lord Alcester desires him to inform Colonel Warren that the Lords of the Admiralty ‘are very grateful to him for the energy, courage, and good judgment with which he has prosecuted the inquiry, under circumstances of considerable difficulty and danger.’ And again on 1st January 1883 Captain Stephenson, the senior naval officer, conveyed their Lordships’ ‘high appreciation of the manner in which Colonel Warren had performed the difficult task of ascertaining the fate of Professor Palmer’s party.’ Captain Stephenson, who was at Suez when the search was going on, added: ‘I wish to add my testimony to the patient, but energetic and persevering, manner in which you have traced the sad fate of the missing party, against many adverse circumstances in a part of the country so desolate that assistance from me would have been of no avail had any untoward circumstances occurred to your party.’