In the finale of Monarch: Legacy of Monsters, not Monarch but Apex Cybernetics receives Cate, May, and Keiko when they return from Hollow Earth.
Tim, Kentaro, and Hiroshi join hands with Apex to investigate the disappearance of Cate, May, and Shaw, a move unexpected by May.
May, in the past, has claimed how vicious Apex Cybernetics, formerly known as AET, can be.
Tim’s decision to seek help from them stems from the mistake that Monarch continues to repeat.
Monarch goes back to their old ways
After Cate, May, and Shaw go missing in Kazakhstan, Verdugo stops looking for them altogether.
Now that Shaw is no longer a problem, she plans to focus on the radiation elevation in other Monarch outposts caused by Shaw initially trying to close them one by one.
She lets Kentaro know that his time in their world is over. Verdugo goes back to being how she and Monarch were.

Keiko, who is still alive and in Hollow Earth, is sending signals. Verdugo doesn’t entertain those signals and refrains from thinking that there could be someone down there who might know better than them.
Tim does his best to convince her not to become what Shaw thought they are. When Verdugo threatens to fire him and he realizes that he can’t do anything, he quits.
Enter Apex
Tim recruits Kentaro and Hiroshi so that they can investigate these signals. They know Monarch won’t help them, but there is another organization researching the Titans.
Tim, Kentaro, and Hiroshi seek Apex Cybernetics’ help to bring Cate, May, and Shaw back home safely if they are alive.
Except Shaw, Cate, May, and Keiko return home alive. They find themselves at an Apex Research Station on Skull Island. However, two years pass by by the time they return.

Earlier in the show, Monarch cut a deal with Apex to save May. The deal could have pushed Apex’s research forward, and in the next two years, they became capable of bringing humans back from Hollow Earth.
It is hinted that Tim, Kentaro, and Hiroshi are now working with Apex, something May won’t approve of, as she has a past with the organization.
Also Read: Natalia Verdugo: Monarch: Legacy of Monsters character explained
