mantel is also responsible for leading the operation to kill den, after it is thought that he had grassed up the firm for the dagmar fire. gregory is an intelligent man, and is able to work out the connection between den and michelle fowler (susan tully), and that she might be the key to finding him. he orders that michelle be tailed, and she was followed to the walford canal. mantel then co-ordinates the assassination via a walkie-talkie. mantel gives the order to shoot den, but 14 years later it is revealed that his attempt to kill den was unsuccessful and he promptly returns to walford in september 2003, and that the body found in the canal in may 1990 was that of mr vinnicombe, who had been killed on the orders of jack dalton after discovering that den had survived.