Unknown Hostile

A distress signal comes out of Black Ridge Research Station.

Security breach. Multiple casualties. Unknown hostile presence.

And one warning no one can explain:

Do not trust visual identification.

Staff Sergeant Ronan Mercer and his reconnaissance team are sent into the remote Pacific Northwest wilderness with seventy-two hours to locate survivors, determine what happened inside the classified research facility, and secure the site for extraction.

They expect armed hostiles. Sabotage. Maybe a containment failure.

They are not prepared for something that can wear a human face.

Deep beneath Black Ridge, researchers uncovered an organism capable of imitation. First it learned sounds. Then voices. Then faces. By the time containment failed, imitation had become something far more dangerous. The creatures do not simply look like the people they kill. They learn them.

Their memories.

Their relationships.

Their fear.

Their love.

Soon the team is hearing familiar voices in the trees. Dead men return to camp. Survivors know things they should not know. Every reunion becomes an interrogation, every memory becomes a test, and every person who disappears might come back looking exactly the same.

Including Ronan.

Including Sergeant Tavian Cross, the medic who knows Ronan more intimately than anyone else on the mountain.

What exists between Ronan and Tavian has always been deliberately uncomplicated. They work together. They sleep together. They don't give it a name. But Black Ridge turns intimacy into a weapon. When something can reproduce a voice perfectly, carry private memories, and imitate the touch of someone you trust, knowing a person better than anyone else may no longer be enough to prove they are human.

As the mission collapses around them, the rules become brutally simple: no one goes alone, no familiar voice is automatically trusted, and no one gets close without proving who they are.

Then the team discovers the worst possibility of all.

The creatures may not simply be copying people.

They may be becoming them.

With communications compromised, extraction uncertain, and the infection already moving beyond the mountain, Ronan and his team are forced back toward the place they were sent to investigate. This time, they aren't going in to rescue anyone.

They're going back to burn Black Ridge to the ground.

But destroying the station cannot answer the question that follows them out:

If a copy has your memories, your loyalty, your fear, your love, and absolutely believes it is you...