A good practice is to switch frequently between times to get a sense of both when and where everything is. However, since some items are in the same place at both times, it's easy to lose track of exactly what's what. Note: The Heart can only detect runes and charms in whatever timeframe it occupies- if you're in the past, it won't tell you that the safe you just opened holds a Rune in the present. Not that runes are a lot of help right now. Let her guide you upstairs to the nearest rune, and your first of the level ( Rune 1/4). The Heart still works here, though she has little to say about the place. There are no enemies on the grounds, so explore at your own pace (though there is a nest keeper behind a grate on the second floor- he can't attack but he can detect you, so ghosters should step lightly). The first such spot is just inside the main door, where one of those popular non-locking safes holds some coin and whalebone. In any case, you're without so much as Dark Vision to mark your path, so you'll have spot your own lootables for a while. Corvo says he can feel the Void leaking in. Funny business, as it turns out- the Mansion seems to sap you of your power. No waking up aboard the Wale this time, it's straight to business.