Ravnica, the city of guilds, is a massive and endless city that spans its entire world. Growing up on its outer edges, you have known the diversity and the chaos that Ravnica contains all your life. It is a world populated by everything from angels to goblins, and greatly influenced by magic -- Izzet electrical elementals rage through the streets, Gruul giants stage riots as acts of political protest, Simic biological experiments spill out of the undercity and wreak havoc, Dimir vampires and Orzhov spirits and Golgari zombies all stalk the streets at night. In all, it is by nature chaotic. What keeps order within that chaos are ten guilds, sworn to protect and provide for the city's welfare, each in their own way. These ten guilds are naturally fiercely competitive and often at odds both philosophically and physically, but a magical contract known as the Guildpact, which currently resides in the body of a dragon known as Niv-Mizzet, forbids the conflict between these guilds from advancing to threaten the city as a whole.
However, the guilds have recently failed to keep Ravnica entirely safe. A recent invasion of Ravnica by a mass army from another plane, Phyrexia, exposed Ravnica's weakness, and greatly damaged the guilds that rushed to Ravnica's defense. Though the invasion was repelled, the city needed to rebuild, and as the guilds struggled to shore up their own ranks, the guildless took matters into their own hands, organizing to take control for themselves of the rebuilding effort. One part of this reform process was a new "detective's agency" being formed, a community-led law enforcement group that would assert new soveirgnty over the usual lawkeepers of the Azorius and Boros, and would help curb the advancing spate of crimes in the wake of the invasion.
You've lived, or have recently moved to, Precinct Six of Ravnica's Tenth District, by all accounts the hardscrabble outer edge of the city's heart, a mostly working-class place where industry runs through the Smelting Quarter. In your time here, you've learned the importance of a hard edge and keeping on your toes, as the chaos of the city can appear at any moment, in the form of a monster or demon or common criminal, though Precinct Six is generally populated by honest, hard-working folk. You have found that interventions by any of the guilds have been rare; they seem too busy or are just plain uninterested to concern themselves with matters in Ravnica's poorest precinct.
This has all led to an unusual development. The aforementioned detective's agency has issued a public notice that there have been multiple reports of a missing angel somewhere in the Sixth Precinct. The angel hails from the Boros Legion, being formerly one of its lieutenants. The agency is short on staff, but still wishes to take the lead on an investigation, and is asking for volunteers with "certain skill sets" to form a community task force to look into the angel's whereabouts posthaste, with a significant reward being promised for fulfillment. Regardless of whether or not there is an angel, this could be well-paying work, and even distinguish yourself in the eyes of this detective's agency, any onlooking guild, or in the eyes of yourself, as self-esteem is most important.