During the Jan6 riot, the Secret Service tried to get Mike Pence into a car with agents that Pence didn’t recognize. The worry was that the agents were either rogue, or working directly for Trump.

Either way, Pence refused to get into the car because he knew he had to certify the election, which meant he had to stay in the building. His worry was that rogue agents (or agents taking orders from Trump) would spirit him away and prevent him from certifying the results.