(mostly from a dream, my dreams can be cinematic)
Two situations occur concurrently:
In Africa a bunch of missionaries get taken hostage.
In the USA, the same religion has a compound full of idiots who adulate their cult leader.
The cult leader decides to kidnap people who are important to the African hostage taker. Turns out he has business interests globally, and actually runs a major newspaper in the mid-size city they live in.
(this is meant to be silly)
The cult leader and his followers raid the 7th floor offices of the newspaper, with the intention of taking hostages.
Now we get to the black humor…
They decide to enter the building via the stairwell to avoid the cameras. The cult leader trips, falls and dies. His followers panic and leave him.
At the 7th floor the followers burst in and do the bank heist thing, everybody down, nobody more, and so on.
Meanwhile someone has found the cult leaders body in the stairwell, and cops arrive – that other story can write itself…
The followers are not smart, clueless without their leader. Someone takes charge.
Knowing that the bus they have outside only takes 20 people, the leader tells everyone that anyone who even looks at him sideways will be killed. Killing will occur until just 20 people remain. Indiscretion killing occurs for the most minor of reasons.
One follower is tasked with taking two journalists to the comms room to switch everything off. The journalists overcome the follower and kill him, then run and hide.
That’s as far as my dream went but the rest shouldn’t be hard. Think Keystone Kops as modern fanatical idiot terrorists, as a lesson on what happens when followers are left without a leader