Even the most passionate of fans will concede that over the course of six years, LOST has become an progressively exasperating puzzle to solve, but solve it they must. Sure, a couple pieces might get lost between the sofa along the way, but as the big picture begins to take shape in the programs final episodes, the most grandiose mysteries that encompass the survivors of Oceanic Flight 815 are beginning to come into focus in bold, unexpected ways.

No mystery, however, has been more profound and affecting than the journey of John Locke. Once a tragically crippled man angry at the world, then a born-again spiritual penchant to the island, and now… the smoke monster? It’s true. The island’s supernatural security system of sorts — a murderous, elusive column of black smoke — has baffled and intrigued viewers since the shows first episode (long before they ever knew what it was). Presumed at this point to be a mystical incarnation of the benevolent Jacob’s nemesis (dubbed the “Man in Black”), who duped Ben — in the guise of Jack’s father — to kill John Locke, eventually inhabiting Locke’s body as a duplicitous loophole of sorts… eh, see what I mean? Exasperating.

Thankfully, Entertainment Weekly sat down with Terry O’Quinn delve into the secrets about Locke, Un-Locke, Smokey, the Man in Black, whatever you want to call him, and to a greater extent, what it has been like to play a character whose motivations are constantly shifting in one of the most elaborately constructed shows in television history. Enjoy.