It can be dangerous trying to send someone a message. Spoken words may be overheard, written correspondence may be intercepted, and body language may be seen. Did you ever wish you could think the words and they would be known?
Gareth turned and squinted uneasily over his shoulder. He could have sworn he heard a high pitched hiss. He turned back to continue through the dim underground passageway. It was then that he saw them. A pair of ruby red eyes, glowing faintly a few feet front of him. He had to look up to see them, and that is saying something, given Gareth’s generous stature. The strike was quick…he had no chance. The last thing he remembered were the eyes hovering above him and the fangs dripping venom. And was that a second set of eyes gleaming beneath the first…?
You find a patch of edible funghi. They taste well and all, no ill effects. UNLESS you consume some beverage, even 3 (three) days after eating it. Then you become really sick with pains, vomiting, all the fancy stuff. As a gift or good meal, it could be a cruel joke or to make sure the heroes spend their time focused on the mission. And the fine soup you had in the inn yesterday could have some in.
(Inspired through a real-world fungus. Was really used to cure alcoholism.)