Pulling an Indiana Jones
When you don't know what you are doing so you just improvise.
Indy: "Get back to Cairo, get us some transport to England. Boat, plane, anything... Meet me at Omar's. Be ready for me; I'm going after that truck."
Sallah: "How?"
Indy: "I don't know I'm making this up as I go."

"Do you have any idea what you are doing? "
"No, I'm pulling an Indiana Jones! "