"The future is in the stars...the possibilities unlimited...the dangers beyond belief!"
— Tag-line, from front cover

The Alien Factor is the second and last book in Hardy Boys and Tom Swift Ultra Thriller series. It was first published by Archway Paperbacks (an imprint of Simon & Schuster) in June of 1993. Produced by Byron Preis Visual Publications, Inc.

Plot summary

Back cover summary:[1]

A Deep Secret From Deep Space Puts Frank and Joe and Tom Into The Deepest Trouble Imaginable...

Tom Swift has caught a falling star---a visitor from outer space who is as beautiful as she is strange. But his secret encounter has set off alarms at the highest levels of government. A top-secret intelligence agency believes he's involved in an espionage and smuggling ring. To check Tom out, the Network sends two of its top operatives: Frank and Joe Hardy.

But when the alien is kidnapped by a sinister industrialist, Frank and Joe and Tom realize that they have to work together. They're dealing with a conspiracy that stretches from the farthest reaches of space into the deepest recesses of their own government. The fate of the country and the planet could rest on uncovering the shocking truth about the girl from another world!


This list is incomplete, you can help The Hardy Boys Wiki by expanding it.


Harlan Ames
Rick Cantwell
Dan Coster
Mandy Coster
The Gray Man
Frank Hardy
Joe Hardy
Mina (aka M'na)
Rob the Robot
Mr. Sunshine (aka Eric Laidlaw)
Mr. Swift
Tom Swift


Burger Master parking lot
Central Hills
Nevada Desert (location of Eric Laidlaw's home, Solitude)
San Diego

Businesses and organizations

The Network


T'wikt'l (species)


  • Because the timeline was reset at the end of A Hardy Boys and Tom Swift Ultra Thriller: Time Bomb, Frank, Joe and Tom have no memory of the events that happened in that book, except for what occurred in the last chapter when Fenton Hardy and boys went to see Mr. Swift and Tom about a shoe print that had been found near some dinosaur tracks.
  • Joe has a cold at the beginning of this book.

Books Referenced

The following books were referenced to in the text of The Alien Factor:

The Hardy Boys Casefiles #1 Dead on Target
The Hardy Boys Casefiles #6 The Crowning Terror


  1. A Hardy Boys and Tom Swift Ultra Thriller The Alien Factor
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