|Functions||Lieutenant of the MCP's army|
|Allies||MCP, Sark, Guard|
|Out of universe information|
Sark's Lieutenant is the quarternary antagonist in Tron. He was an ENCOM program who operated as Sark's right-hand-man and lieutenant. He was a specialist in protocol and intelligence. His original user was Peter, Ed Dillinger's assistant. Sark called the Lieutenant "Null Unit" and "bit-brain," criticised him for showing initiative, and occasionally struck him in fits of bad temper.