I was referring to their carpentry efforts discussed in Cold Days. In Cold Days, Harry mentions building the dock along with Thomas, on weekends when the two of them would come to the island and work on it, prior to when he was shot at the end of Changes. But Harry doesn't claim the island as his sanctum until the events of Turn Coat, and by that point Thomas has been captured and tortured by the naagloshii. He mentions in Changes that after they got Thomas back, he's only seen him for "two, maybe three minutes" since then. So at what point did they get together to build the dock and start repairs on other parts of the island?