MarkS,

The purpose of a logline is to?sell a script to a moviemaker, not to a movie watcher. Getting them interested? Great. They probably read a lot of interesting loglines. Getting them to want to read your script means you need to convey the plot of the script concisely. The logline should only describe visual actions, the goal of the protagonist. It should raise interest, and shouldn’t be so vague that there are a host of questions that need to be asked to understand what the plot is.

For example, how does he discover his life is based on lies? What does that mean? Lies pertaining to what? Who lied? Why? What do they want? Is it his job? Did his family not tell him he’s adopted? Did his wife marry him because of an ulterior motive? What are the lies, and why do they matter? ?This may seem like nitpicking, or something that will be answered in the script, but by the time a producer has asked themselves these questions they’ll probably move on. ?It’s a simple thing to be specific about.

So that leaves, “but the battle to dig through the past and unravel the truth becomes dangerous and could cost him his job, his family, and his sanity.” That itself is 25 ?words that could be cut by specifically describing what the character’s objective, specific goal, that has a clearly defined ending point.
For example, using some of the elements from this logline but making up my own story:?After discovering that?he is the son of a criminal mastermind, an adopted police chief goes rogue to search for his mother whom he thought was dead. (26)

28 words versus 49. Comparing them:
What lies did the protagonist believe? He didn’t know his real mother was a criminal.
What does he seek to do? Find her.
The climax of the story? He either finds her or he doesn’t. Succeed or fail. Unless he changes his goal during the story. But either way, the logline defines a clear endpoint for this goal. The original post describes the goal as “unravel the truth”. That could imply a number of different things.
A logline should capture attention, it should hook the reader with something unique and interesting, and at the same time it should clearly convey what the story is about. All in as few words as possible.