Like the publishing history, the events in this novel take place about a year after The Return of Tarzan. In the early portion of the novel, readers learn that Tarzan has built an estate home in Uziri, Africa and spends part of his time at another estate in London. Tarzan and Jane also have an infant son named Jack, who was first introduced in the Burroughs novel The Eternal Savage (serialized as The Eternal Lover), which isn't a necessary read to enjoy this Tarzan installment. Jack plays a prominent role in The Beasts of Tarzan, but more as a concept than an actual character.
The book's narrative revolves around two of Tarzan's fiercest enemies, Russian men named Nikolas Rokoff and Alexis Paulvitch. The duo first appeared in The Return of Tarzan, where they were caught and jailed for numerous criminal offenses, including attempts to kill Countess Olga de Coude, Lord Greystroke and his wife. In The Beasts of Tarzan, the two men escape prison (off page), a fact that Paris policeman Paul D'Arnot conveys to Tarzan in an apartment building. These two men manage to trap and kidnap Tarzan, Jane, and a baby (a surprise twist on the Jack kidnapping). Separately, the three are imprisoned on a ship called the Kincaid.
Later, Rokoff transports Tarzan to the isolated Jungle Island where he takes his clothes from him and ultimately leaves him there to die. He tells Tarzan that he will take Jane to be his lover and that Jack will be raised by a tribe of cannibals (harsh!). Thankfully, Tarzan is at home in this sort of savage wilderness. He quickly dispatches a king ape and befriends another ape called Akut. Tarzan also befriends a giant cat (panther?) called Sheeta and a Wagambi warrior named Mugambi. Together, these heroes lead a band of apes against Rokoff, Paulvitch, and their hired henchman. The propulsive plot features these heroes chasing the villains through the jungle and various tribes of savages.
I can't reveal too much in this review, but The Beasts of Tarzan was better than The Return of Tarzan in my opinion. Burroughs' injects so much primitive violence and brutality into his writing, from Sheeta disemboweling enemies to Tarzan's fatal strikes of vengeance. As one would expect, the jungle tribes are filled with nefarious characters ranging from mercenaries to flesh-eating cannibals. I wish the book was slightly shorter, but the events at the end of the book concerning Paulvitch are important elements that set the table for the fourth series installment, The Son of Tarzan. As unnecessary as they may seem, the author had a grand design at work here.
The Tarzan series is quickly becoming one of my favorites, and I'm anxious to read more of what horror, violence, and awe-inspiring adventures await this jungle family. In the meantime, Tarzan of the Apes, The Return of Tarzan, and this novel, The Beasts of Tarzan, are darn-near perfect. If you haven't read these books, you are in for one heck of a ride. Highest recommendation.