Draught of Peace

From UnknowableWiki

The Draught of Peace is a potion used to calm anxiety and sooth agitation; however, adding too much of the ingredients (which include powdered moonstone and syrup of hellebore) can put the drinker into a deep sleep. It is very difficult to brew, with specific directions on the order in which to add the ingredients, the number and direction of stirs, and the level of the heat on which it simmers. When properly brewed, it will emit a silvery-colored mist; however, there are many ways it can go wrong, and various possible negative results.

In the Trio's fifth year, the Draught of Peace is the first potion they must brew in Professor Snape's OWL-level class. Hermione manages, unsurprisingly, to brew it correctly, but not many others are as lucky. However, Snape singles out Harry, who has forgotten to add the syrup of hellebore at the appropriate time to his potion (which as a result is releasing large amounts of dark gray steam), even though Seamus, Ron, and Neville are doing no better (OP12).