In "The Argonaut Affair," seventh of Simon Hawke's 12 "Time Wars" novels, the Time Commandos face monsters, rival versions of themselves from another timeline, and rogue terrorists.
The "Time Wars" stories are a funny and well written series about a group of Time Commandos whose mission is to prevent other time travellers from causing damage to history.
In some of these books, the Time Commandos are up against rogue individuals or groups of terrorists who are trying to subert the past for their own purposes: sometimes they come up against operatives from rival alternative futures who are trying to defend their own versions of history. In this story they come up against both.
All 12 books in this series pay humorous homage to a great work of literature, to a set of historical events, or both. Most of these books go back to the time and events of a classic novel, and revisit the events of that story, usually with an ironic or comic slant. In this case, the main story is the legend of Jason and the Argonauts on the quest for the Golden Fleece, but the main character of "The Island of Doctor Moreau" also makes a cameo appearance.
The books are best read in the correct sequence, as follows (I have put the name of the literary work and/or historical events associated with each book in brackets afterwards)
1) The Ivanhoe Gambit (Ivanhoe)
2) The Timekeeper Conspiracy (The Three Musketeers)
3) The Pimpernel Plot (French Revolution & terror/Scarlet Pimpernel)
4) The Zenda Vendetta (The Prisoner of Zenda)
5) The Nautilus Sanction (20,000 Leagues Under the Sea)
6) The Kyber Connection (works of Rudyard Kipling/early life of Churchill)
7) The Argonaut Affair (Jason's Argonauts/Island of Doctor Moreau)
8) The Dracula Caper (Sherlock Homes meets Bram Stoker's Count Dracula)
9) The Lilliput Legion (Gulliver's travels)
10) The Hellfire Rebellion (American War of Independence/Hellfire Club)
11) The Cleopatra Crisis (Caesar and Cleopatra)
12) The Six-gun solution (Gunfight at the OK Corral)
Not terribly serious but very good fun: I can recommend this series.