When an away team from the Discovery traveled to the Glenn, they encountered a horror show within and were attacked by a giant monster. Referred to as a 'Tardigrade' by Discovery's producers on After Trek, the monster slaughtered Klingon invaders who were looking to steal tech from the Glenn and nearly killed the away team before they were able to escape on their shuttle craft. Unbeknownst to the rest of Discovery's crew, Lorca had Commander Landry secretly beam the Tardigrade on board the Discovery so he can research it further.
In real life, tardigrades (also known as water bears, space bears and moss piglets) are micro organisms known to be one of the most resilient species on Earth. Tardigrades can survive in extreme conditions and some species can even survive in the vacuum of space. The Tardigrade monster in Discovery has been mutated to be much larger and more violent than a normal tardigrade. It's been weaponized, and with its resiliency to nearly any type of environment or harsh condition, the Tardigrade is obviously something aimed to be put to use against the Klingons.
Along with the Tarigrade now imprisoned behind a force field, Captain Lorca has a private 'study' where he keeps numerous creatures and experiments for possible use. Lorca is determined to end the war and is open to any means to achieve his goal and save the Federation. In Lorca's study he has Klingon weapons and items from other species on display, including the skeleton of a Gorn encased in glass, though at this point in the timeline, the Federation has not made first contact with the Gorn, therefore to Lorca, it's just the bones of an unknown reptilian species. But anything that could be used as a weapon against the Klingons - even a Tribble - is in Lorca's interest, no matter how esoteric or even illegal.
Plans for Michael Burnham
In Michael Burnham, Lorca sees exactly the type of person who he thinks both he and Starfleet need to win the war. In Lorca's mind, Burnham's assumption about the Klingons intentions were correct, though she violated Starfleet laws. Burnham choosing to do what was necessary, even above what her orders were or what is sanctioned by the Federation, is what is, in Lorca's words, "the kind of thinking that wins wars." Lorca is thinking and operating on an entirely different level than how a Starfleet Captain would normally be expected to behave, hence his belief Burnham is a kindred spirit, based on her actions on the U.S.S. Shenzhou. In Lorca's mind, the high-minded virtues and methodology Starfleet is clinging to is the reason the Klingons are winning. To Lorca, "Universal law is for lackeys. Context is for Kings."
Even though she's a mutineer, Lorca has the authority to disregard Burnham's life sentence in prison and use her to win the war as he sees fit. Burnham, though reluctant and wishing to serve out her punishment for her mutiny, is also in desperate need of redemption, and her dual training as both a Vulcan and a Starfleet First Officer makes her too valuable a resource to waste away in a penal colony. What lengths Lorca and Burnham will now take together in order to defeat the Klingons are going to be fascinating to to discover.
Star Trek: Discovery streams on CBS All-Access Sundays at 8:30pm ST and on Netflix internationally.