The Alien Factor
Volume #2 in the Hardy Boys and Tom Swift Ultra Thrillers series
- Publication date: 1993
- Summary: The Alien Factor involves "a visitor from outer space who is as beautiful as she is strange" (quoting the back cover). The boys' time-travel exploits in the previous book have conveniently wiped away their memories of the time they spent together, making them near-strangers once again. This allows Frank and Joe to be initially suspicious and distrustful of the Swifts.
Cover art (click thumbnail to enlarge)