Turbo Abstract State Machines are ASMs with parallel and sequential composition and possibly recursive submachine calls. Turbo ASMs are viewed as black-boxes that can combine arbitrary many steps of one or more submachines into one big step. The intermediate steps of a turbo ASM are not observable from outside. It is not even clear what exactly the intermediate steps are, because the semantics of turbo ASMs is usually defined inductively along the call graph of the ASM and the structure of the rule bodies. The most important application of turbo ASMs are recursive algorithms. Such algorithms can directly be simulated on turbo ASMs without transforming them into multi-agent (distributed) ASMs. In this article we analyze the hidden intermediate steps of turbo ASMs and characterize them using PAR/SEQ trees. We also address the problem of the reserve in the presence of recursion and sequential composition.