Do your homework before you make a decision. Secrets are definitely in the air: secrets of all kinds. A coworker who's been putting out some rather mysterious signals lately will have you wondering what they're up to. If you've known them for a long time and you tend to trust them, don't get carried away: especially if you don't have all the facts. If you're not quite sure about them, based on past history, you still shouldn't make rash judgments.