Crime Boss: Rockay City

Each time you do a Baker's Battle run, there is a chance for a couple mission sets to unlock for several different characters (each with there own achievement tied to them). Once you've completed a mission in a character's chain, you will NEVER have to do it again. Even if you fail the run before completing the whole mission chain for a given character; next time you are given that character's mission, it will be the next mission in the chain after the last one you completed. The only character mission chain I expect to re-occur during probably every run is for Wiz; because it is tied to the Hidden Vault grand heist. As a note, since I can't recall anymore, you may have to purchase a couple of these by selecting them during Boss Level-Ups - then purchasing them.

These stories seem to be randomly assigned to you each run. In my experience, you only get 2 of them in a given run. In theory, you could speedrun the first few days of "Baker's Battle," testing which stories they give you; then restart if you didn't get the one(s) you were hoping for. I had to figure a lot of this out on my own with not a lot of explanation, so here's something that may be true, but I'm not sure: some characters need to be unlocked, and then purchased, in order to begin their mission chains. I am fairly confident this is how things are with Ranger specifically, because I completed his "Urban Legend," which made him available for purchase in "Baker's Battle." His first quest appeared after I purchased him for my team in a run. I'm just trying to be helpful to anyone lost like me - I don't have as many concrete answers as I would like.

This can be confusing if you don't know what to look for. When playing the campaign, background missions for five characters will randomly appear. These are marked in light yellow on your map (see screenshots below)

The story arc for Cracker contains five missions: "Hook Up", "Jet Set", "Dish Order", "On Rails" and "Caving". I believe they become available once Cracker is on your team, so keep an eye out if he's available. When you complete the first one, the second will appear one or two days later, and so on. You will get the achievement after finishing the last mission.

Below are screenshots of all mission markers for Cracker. The location on the map is random, but this is what you're looking for.

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Note: another solution says that a mission will never appear again if you complete it but fail the campaign partway through the character story arc, but that has not been my experience.