detective agency, Pinkertons, bank robbery, investigation, vintage attire, magnifying glass, documents, secret informants, covert surveillance, eavesdropping, shadowing suspects, analyzing clues, old-fashioned revolver, discreet communication, stakeout, 19th-century town, horse-drawn carriages, dusty roads, saloon backdrop, western genre, sepia-toned lighting, wide-brimmed hats, leather boots, period-specific architecture, intense gaze, focused expression, dynamic poses, action-packed scene, high contrast shadows, sunset ambiance, dramatic tension, detailed textures, historical accuracy.