This chapter starts on the rooftop of the [Dayport - Rooftops] location and its starting part will be quite linear. Take several steps ahead and watch a short cutscene, which will fill you in on how to get to the Architect's nearby estate. Start walking over the successive rooftops, climb onto the balcony above jump down to the cornice below. Along your path, keep looking around for the side balcony, which it is worth exploring to find a Tea Cup - 4G and an Ashtray - 8G. Jump towards the nearby cornice, jump down to the balcony below and go North.
After you see the explosion in the distant tower, jump down to the fragment of the roof below and turn left. In the spot shown in the above screenshot, Garrett can use the rope arrow. Slide down the rope to the very bottom and explore this optional area [Dayport - Passage] thoroughly, thanks to which you will obtain a Pocket Watch - 50G, an Water Arrow) stored in the locked crate and a ring (Serendi Stone Circles - Lapis Lazuli Circle) under the bench. Return to the rope and climb up to get back to the rooftop. Explore this location to find a Poppy and leap towards the window to the North. Finally, squeeze between the crates to reach, eventually, the vicinities of the Architect's house [Eastwick's Grand House - Garden].