Cigars of the Pharaoh: Part 2 - S1-E7
Continuity mistake: At the start of the meeting, there are 7 people including Tintin. With the exception of Tintin, this makes 6 people. After Tintin finds out the identities of the brotherhood, there are 7 people with the exception of Tintin. Tintin did take someone's clothes, however all the people there are dressed in their robes and Tintin is dressed in the robes as well. (00:38:45 - 00:40:00)