Milgrim’s shoes slipped on bricks worn cornerless with years. He followed Brown up three high granite steps cupped by centuries of feet. The black-painted door, beneath a simple fanlight, was decorated with a Federal eagle in recently polished brass, so old that it resembled no eagle Milgrim had ever seen, but some creature out of more ancient mythology, perhaps a phoenix. Cast, Milgrim guessed, by artisans who’d never seen an eagle, only some engraving of one. Brown’s attention was entirely taken up, now, with a keypad of brushed stainless, set into the jamb, on which he was entering a code he copied from a slip of blue paper. Milgrim looked up the street and saw expensively old-fashioned streetlights wink on. Somewhere up the block a very large dog was barking.