When the Third Doctor determined that the strange sounds were alien messages and had to be recorded and deciphered, Bruno pulled a gun on him and Liz Shaw, demanding that the Doctor turn over the tape. Later, when General Carrington came into the picture, Bruno said that he was ordered to take the recordings by Carrington. As the General was clearly involved in an illegal operation, he was drawn in deeper and deeper into his nefarious activities. He kidnapped Liz and brought her to Reegan, Carrington's henchman, to help them communicate with the captured aliens.
Later, when the Doctor began to suspect him of being involved with the people causing all the problems, he went to Reegan to tell him of the Doctor's suspicions. Reegan, seeing that Taltalian was in danger of being found out and beginning to waver, prepared a bomb in a suitcase to kill the Doctor and Taltalian. Taltalian brought the suitcase to the Doctor, but, not knowing that Reegan had set the bomb to explode immediately without the timed delay that Reegan spoke of, he turned the levers on the suitcase. He was killed instantly, but the Doctor survived. (TV: The Ambassadors of Death)
Before he died, he received a letter from the Apocalypse Clock which predicted the exact date and time of his death. Liz's mother Dame Emily Shaw described him as being "not one of nature's charmers." (AUDIO: The Last Post)