First Contact with an alien species can happen in a grand moment of scientific discovery, like in the film "Contact." It can also happen in a much more mundane and accidental manner.
Adrian Mast is an aeronautical engineer (and frustrated astronaut). Browsing in a local bookstore, he picks up a remaindered book on UFOs. In the Appendix, Adrian finds what look like a legitimate set of plans for an interstellar spaceship. With help from Frances Farmstead, the bookstore's owner, Adrian tracks down the publisher, who nrevously denies that they ever published the book, even though their name is on it. Peter Cavendish, the author, is in a mental hospital in the Midwest, afraid that the government, or the aliens, is out to get him. Somone has gone to a lot of trouble to suppress the book. Adrian and Frances get the plans spread out to the scientific community, before someone "suppresses" them.
The alien machines built from the plans radically change Earth, bringing about an era of really free energy. Adrian and Frances put together a group of people to build a spaceship based on the plans. They get permission from the Energy Board. Cannibalizing an old space station, the ship is finally ready for launch. Mankind still has no idea who the aliens are, where they are or why they sent the spaceship plans. On its maiden voyage, the ship suddenly starts traveling in a very different direction. Before he left the ship, back at Earth, Peter Cavendish programmed the ship's computer to take the ship to the aliens.
The ship enters a wormhole, where the laws of time and space are turned upside down. There is no way to tell how long the wormhole is, or if the ship is even moving. The crew remembers events that haven't yet happened. The ship eventually leaves the wormhole, and reaches a planet with hundreds of spaceships in orbit, of all shapes and sizes. Evidently, humanity was not the only civilization to hear from the aliens. After months of waiting for a reception committee, which never happens, members of the crew land on the surface, find their way into underground tunnels, and get some answers to their questions.
This one is very plausible and rational, and it has believable characters. It is interesting from start to finish, and is very much worth the time.