Read "The Man who was Thursday" by G.K. Chesterton online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
Next morning five bewildered but hilarious people took the boat for Dover. The poor old Colonel might have had some cause to complain, having been first forced to fight for two factions that didn't exist, and then knocked down with an iron lantern. But he was a magnanimous old gentleman, and being much relieved that neither party had anything to do with dynamite, he saw them off on the pier with great geniality.
The five reconciled detectives had a hundred details to explain to each other. The Secretary had to tell Syme how they had come to wear masks originally in order to approach the supposed enemy as fellow-conspirators.