Meet my Hatchet of Death (or, some other colorful description RC Lewis and I come up with at any given moment). This is how I edit myself, it is how I edit others. If you think you want to play with me and my hatchet, shoot us an email.
We all know the first line of a query is your "hook." I call the last line the "sinker." You want it to punch them in the face, in a nice, friendly kind of way that makes them unable to forget you after having read the 300 other queries in their inbox.
If you're looking for query advice, but are slightly intimidated by my claws, blade, or just my rolling googly-eyes, check out the query critique boards over at AgentQueryConnect. This is where I got my start, with advice from people smarter than me. Don't be afraid to ask for help with the most critical first step of your writing journey - the query. My comments appear in green.
In SUFFER THE CHILDREN, Alex, a recovering alcoholic, is slowly regaining horrific lost memories, memories that could expose a decades old ring of human trafficking. Cool. I'd rephrase slightly to get rid of the "memories" echo, but this is a succinct, straight-forward hook with interest.
Thaddeus Cahill lured thousands of Mexican immigrants onto his land, promising them a better life, and then betrayed them by using their bodies as fodder to create a formula, which could clone humans to anyone’s liking. If in the wrong hands, this formula which enables the cloning of humans of any gender, age, or level of intelligence, could be used to create an army of evil in a greedy bid for power, encompassing sexual trafficking and human experimentation. Thaddeus Cahill’s grandnephew is seeking the formula, and his intentions are vile and nefarious; and he’ll destroy and annihilate anyone who attempts to thwart him in his quest. You definitely need to revisit some of these sentences and trim them down. There's some excessive comma use and unnecessary phrases at work here that make for run-ons that might provide more detail than necessary. I'm also confused about who Cahill is, exactly. The fact that he's a land owner in Texas (I'm assuming) automatically makes me think "rancher" but then he's cloning people. So now I've got this picture in my mind of a dude in a white lab coat wearing a Stetson. Probably inaccurate.
Alex must find the formula and destroy it before Cahill’s grandnephew does. If Alex fails, the consequences will be disastrous. You've got the plot out here, but I don't know jack about our main character other than 1) he knows things 2) he drinks. How does he know things? Did he work for Cahill? Was he a coyote? Was he a victim? Is he a clone? I definitely need to know more about who this person is and what's at stake for them personally -- is this revenge? retribution? contrition?
Get more character into this query, for both the good and bad guys. Thaddeus Cahill's rancher/scientist character is present, along with motives- but since his grand-nephew is actually the bad guy in the book we should be talking about him... and we don't even know his name.