Big cat biologist Alexander Braczkowski is on a mission. He's got 90 days to count lions in Uganda and learn how the population is doing. But these aren't ordinary lions. The prides in Queen Elizabeth National Park spend most of their lives up in the trees, a rare and mysterious behavior unique to this part of Africa. On his journey, he'll witness mothers battling the odds to raise cubs through their first year of life, and the threats tree climbing lions face as the human population expands. Alex's experience will become more personal than he could have imagined, and he'll learn that saving lions can be about much more than counting cats.