The Dangerous Return, Ch. 1 cliffhanger ending - Snark knocks Nyoka out by hitting her on the head with his gun. His partner, Boojum, tells him to get rid of her. Snark carries the unconscious girl to the edge of the ship and then he throws Nyoka into the raging waters of the ocean. As the writer puts it, "No human can remain long in the swirling sea off the Jungle Island of Doom."
Ch. 2 cliffhanger ending - Two headhunter natives seize Nyoka, each holding one of Nyoka's arms. They plan to behead her!
Adventure in Burma, Ch. 1 cliffhanger ending - Three of the Maharaja's men have Nyoka and Larry Grayson trapped against the wall, as they raise their swords to kill them.
Ch. 2 cliffhanger ending - Nyoka is on a ladder that leads into a deep well. The Maharaja orders one of his men to set the ladder on fire. Swiftly the ladder is engulfed in flames and the fire encircles Nyoka, even spreading to her clothes!
Note: This photo cover of Clayton Moore and Kay Aldridge comes from a scene in the Republic Serial, The Perils of Nyoka, aka Nyoka and the Tigermen.
— Description from Comic Vine community (comicvine.gamespot.com).