I explained the basic premise of the series in my playthrough of the mysteriously fourth book, The F.E.A.R. Agency, but as each book reuses the same half-dozen pages of introduction, I think I can get away with spelling it out again here. My character is a child who gets recruited into a top secret organisation dedicated to foiling the plans of Triton, a time-travelling alien who wants to mess with Earth's past and future because he's a villain.
In Agency it was technically impossible to fail because the adventure consisted of a series of simulated missions carried out in virtual reality, and going wrong just meant having to retake the test (only I refused the retake because gamebooks should have some bad endings). In the rest of the books, the missions are for real, but it's still not possible to fail (except by treating the 'go back to section 1 and try again' instructions as the defeats they should be) because if I ever mess up, the time machine that F.E.A.R. use to send me on the mission will be used to rescue me. No explanation is provided for why it's never used to rescue any of the adult agents whose capture forced F.E.A.R. to start recruiting children.
My mission starts with a trip to the island of Santa Diana, off the coast of Cuba. Apparently it's the location of the world's most important naval base, which is why Triton is attempting to conquer it in 1720. With the help of F.E.A.R.'s time machine (a duplicate of Triton's, based on one that F.E.A.R. captured in ancient Egypt - I wonder how the agents who seized it managed to travel back in time to be able to do so) I'll be sent back to 18th century Santa Diana to foil Triton's scheme or
I'm given a device that should help me to find the 'time chip' that allows Triton to remain in the era, and can also take one of three other items with me: a compass, a telescope or a bag of gold coins (of course there's no explanation for why I can't take all three). I pick the telescope, and enter the time machine. It's on board a boat, and I'm the only person to realise that the boat won't be there when I arrive in 1720, so I'll fall into the water. Let's hope that the chip locator has been waterproofed.
The inevitable soaking does me no harm, and I swim to a nearby jetty. There's a fisherman dozing close by, and I wake him in order to ask some questions. Despite being aware of my location, I ask him where I am before more usefully asking for directions to town. He answers the first question correctly, but then rather than actually providing directions, he tells me how long it will take to get to town - or how long it would take if I actually knew which way to go. Undeterred by the unpromising start to the conversation, I keep talking, learning that the sailor is Hop-Along Jones (yes, he does have a wooden leg), a pirate in the service of Captain Green. He attempts to recruit me, and I turn him down. The book has me do so with unnecessary rudeness, in a manner that clearly shows me to be hostile to pirates, and as I now know too much, Hop-Along attacks me with his previously unmentioned stick. That's apparently enough of a threat to prompt F.E.A.R. to extract me from the situation, so I get dragged back to the present day.
So that's it for my first proper mission for F.E.A.R. As endings go, 'almost got poked with a stick by a pirate' is pretty underwhelming, but it's an excellent illustration of the problem with gamebooks that try to avoid imperiling the reader's character.