The Convention sent Jean-Baptiste Carrier to Rennes to re-establish order. He arrived on 1 September and remained until 5 or 6 October, when he left for Nantes. In the intervening five weeks he rallied the local Jacobins and comprehensively purged Federalists, Girondins and monarchists from every public office. There were no executions under his command, although counter-revolutionaries were locked up in various local prisons - the most dangerous among them being confined to Mont Saint Michel for maximum security - and others were sent to Paris for trial. He waged a particularly intense campaign against the local clergy, and had plans for a "noyade" (mass drowning) as he was later to undertake at Nantes, but he could not put his plan into effect because any vessel leaving St. Malo would have been easily captured by the British fleet which was standing out to sea, imposing a blockade. After Carrier's departure, his replacement released most of the people he had imprisoned.