Quick answer

Treat They Grow Up So Fast as a four-season campaign spine, not four separate one-shots: map the seasonal beats first, tie each mystery to one Kid's personal question, and prep only the clues and NPCs that season needs. The steps below give you an order that keeps the table moving without overbuilding.

Why the seasonal structure changes your prep

The campaign spans the seasons of a year, so the same town, the same school, and the same friendships carry forward. That continuity is the point: a mystery solved in spring should leave a mark that the players feel in autumn. If you prep each adventure as a closed case, you lose the slow change that makes the campaign feel like growing up.

This also means you should not front-load every secret. Hold back at least one consequence from each season and bring it back later as a familiar face, a changed location, or a question a Kid thought was settled.

Keep the Kids at the center, not the strangeness

The strange events are the hook, but the emotional weight comes from what the Kids want and fear. Before each session, write one sentence for each Kid that names a personal stake in the current season. If a scene does not touch any of those stakes, cut it or move it to a later season.

Teen mysteries in this game work best when the players make choices that cost them something socially, not just physically. Prep a few NPC reactions that can escalate or soften based on how the Kids treat friends, parents, and teachers.

When to slow down and when to skip ahead

If your group meets rarely, compress the connective tissue between mysteries and open each session with a short seasonal montage. If your group loves roleplay, let the town breathe and use the quieter scenes to plant the consequences you will call back later. The tradeoff is real: more town time means fewer mysteries per season, so agree on the pace before you start.

Your step-by-step prep sequence

  1. Read all four adventures before you prep the first session: Skim the full campaign once, noting which NPCs, locations, and consequences recur across seasons. Do not memorize stat blocks yet; just mark the through-lines. Checkpoint: if you cannot name one thread that survives from the first adventure to the last, reread the transitions before you run anything.
  2. Assign one personal question to each Kid for the year: Write a single open question per Kid, such as who they trust or what they are afraid to lose. Keep it visible behind your screen and revisit it each season. Checkpoint: every session should push at least one Kid's question forward, even if the answer is 'not yet.'
  3. Map each season to a single mood and a single pressure: Give each season one dominant feeling, like discovery or distance, and one pressure that builds, like a friendship straining or a parent noticing too much. Write both at the top of your season notes. Checkpoint: if a scene serves neither the mood nor the pressure, cut it or save it for a later season.
  4. Prep only the clues and NPCs the current season needs: List three clues that point toward the season's mystery and two NPCs who can deliver them. Leave the rest blank so player choices can fill the gaps. Checkpoint: if your prep notes run longer than one page per session, you are overbuilding for a kid-scale mystery.
  5. Plant one consequence from each season to pay off later: After each adventure, write one sentence describing what changed in the town or in a relationship. Bring that change back in the next season as a visible detail. Checkpoint: by the final season, at least three earlier consequences should be active at the table.
  6. Open each session with a short seasonal check-in: Ask each player what their Kid has been doing between mysteries and what they are worried about. Use their answers to adjust the opening scene. Checkpoint: if a player's answer surprises you, that is a signal to fold it into the current mystery rather than ignore it.

Campaign product at a glance