I'm five sessions into DMing my first campaign, and the suspicious nature and malign intent of the player characters makes it so wonderfully easy to create more story hooks.
I figured out the larger story of the setting a few weeks ago (it's in the Forgotten Realms, and some cool lore-based shit is going to happen), but for now the party is mostly caught up in intrigue with a group of anonymous ne'er-do-wells in this small village. They misdirected and beat up guards to seize control of one of the two guard towers in town, just for the chance to spy on what some of them have chosen to treat as nemeses
Attacking the town guard, eh? If you can't use that like Junkenstien uses a crowbar, hang it up.
They are obviously desperadoes and now outlaws. They should start seeing wanted posters of themselves soon. Bounty hunters are a thing.
There were these guys in suits, who introduced themselves by the name of their pattern of choice (Argyle, Paisley, and Gingham), lying and cajoling the party into doing their bidding--but consistently paying. The party's half-orc monk (he's a conflicted dude) got pissed at being duped and ran to confront them alone. He's going to wake up in a pine box. Another party member, a gnomish drug dealer, tried to out the "suits" to one of the guards after beating the guard within an inch of his life. An arrow from elsewhere finished the job, and now there's an investigation underway.
Mostly the suits have been using them for a harassment campaign that culminated in an assassination of someone who left their ranks. That's the only reason the suits were in the town in the first place. Now they are gone, their suits left behind and anonymity fully restored, and the party has been paid with a strange bauble containing a very old map of Faerūn. With it will come the first inklings of the main arc. Differences in the map vs. the present-day landscape will lead the players to certain artifacts from the lost Empire of Netheril, and meddling in forces they don't understand may draw the attention of Netheril's ancient enemies, the phaerimm.
Also worth mentioning that the guard could have been a valued asset to a local crime syndicate or guild, also family ties or perhaps lover now UPSET, or the only good factor holding someone or something from taking more bold actions.
Killing cops is just bad.
Good ideas. This town is small, mostly human, and suspicious of outsiders. The players will find it even less hospitable than before, and may finally be run out after this next minor arc (missing townsfolk and a plea for help from the mayor) is resolved.