emirates employee tells law enforcement a man had just paid cash for one-way ticket to pakistan. according to an account provided to cnn by a federal law enforcement source, here's what happened next. as the plane is boarding, agents are moving in. the decision is allow the plane to shut its doors. before the plane can push back, sources tell cnn, the door is reopened, faisal shahzad is placed under arrest and removed from the flight before it ever leaves the gate. now, under intense questioning, another emergency, two more names on board the emirates flight appears suspicious. out of an abundance of caution, the plane is told to go back to the gate. >> i have a message for you to come back to the gate immediately. >> reporter: two individuals removed, questioned and let go. so far, the only arrest made is faisal shahzad. he is said to be cooperating with the investigation and detailing his travels and training. >> he's apparently talking about