Il était une fois contains scenarios and gamemaster aids about Space-Time Continuum travel.
After a short explanation of time travelling and parallel universes and a presentation of the means of travel used by the different factions, the book offers four scenarios to take the players to different times and places:
- "Alouette, gentille alouette" has a team of angel characters sent to protect Joan of Arc
- "Accroche-toi aux clous, j'enlève l'échelle" asks a team of angels to make sure the crucifixion of Jesus happens
- "Reviens Georges, j'ai les mêmes à la maisons" (for demons or viking characters) is about saving the last dragon and the last fey folk from the armies of Georges, Archangel of Purification
- "Le Pouvoir Derrière La Croix" (also for demons) has the players take part in an Inquisition tribunal in 1322 in order to save a jewish merchant
The book also contains three new Archangels (Catherine Archangel of Women, Georges Archangel of purification, and Jesus Archangel of God - yes, you get stats for Jesus).