Rex hadn't simply been following orders.
He had been keeping a promise.
The emergency call
A phone vibrated on the table.
Elizabeth looked down.
Her expression changed.
Marcus noticed.
"Who is it?"
She turned the screen toward him.
An unknown number.
One message.
WE KNOW YOU HAVE THE SECOND TAG.
A second message appeared.
LEAVE THE HOSPITAL WITH THE DOG. COME ALONE.
Marcus took the phone.
"Who sent this?"
Elizabeth shook her head.
"I don't know."
General Brooks stood.
"We need to move everyone to a secure location."
Emily looked toward the door.
"What about Christopher?"
Marcus immediately turned.
"Where is he?"
A nurse rushed into the consultation room.
"Dr. Carter!"
Emily stood.
"What happened?"
"Your patient in intensive care has regained consciousness."
Marcus moved toward the door.
"Take me to him."
The nurse hesitated.
"There's something else."
"What?"
"He's asking for Sergeant Cole."
Marcus hurried into the corridor.
Rex followed.
They reached Christopher's room.
This time, two military guards stood outside.
Inside, Christopher was awake.
His eyes moved toward Marcus.
"Little brother."
Marcus approached the bed.
"Don't ever do that again."
Christopher gave a faint smile.
"Do what?"
"Disappear for six years."
Christopher tried to laugh, but the effort made him cough.
Marcus took his hand.
"I thought you were dead."
Christopher squeezed his fingers.
"I know."
"Why didn't you come home?"
Christopher looked toward the door.
"Because I wasn't the only one they were hiding."
Marcus frowned.
"What do you mean?"
Christopher slowly turned his head toward Rex.
"There's another dog."
Marcus stared.
"What?"
Christopher swallowed.
"Another working dog. Same program. Same training."
"Where?"
Christopher looked directly at him.
"At the military research facility."
Elizabeth stepped closer.
"Christopher, you shouldn't talk about that."
He ignored her.
"Marcus, you need to find the second dog."
"Why?"
Christopher's eyes filled with fear.
"Because that dog has the original evidence."
General Brooks approached the bed.
"What evidence?"
Christopher took a shaky breath.
"The names of every person who signed the transfer orders."
He paused.
"Every person who disappeared."
Then he looked at Marcus.
"And the name of the person who ordered our father killed."
The room went silent.
Marcus stared at him.
"Our father?"
Christopher nodded.
"He's not dead, Marcus."
Marcus's face went pale.
"Where is he?"
Christopher looked toward the ceiling.
"He's the one who started Sentinel."
Before anyone could ask another question, the lights went out.
A loud metallic crash echoed through the hallway.
The emergency backup lights flickered on.
One of the guards shouted.
"SECURITY BREACH!"
Marcus turned toward the door.
Through the glass, he saw several figures moving quickly down the corridor.
One of them carried a medical transport stretcher.
Another wore a white hospital coat.
And the third was holding a black case.
Rex began barking.
Christopher grabbed Marcus's wrist.
"Listen to me."
Marcus leaned closer.
"What?"
Christopher's voice became urgent.
"They didn't come for me."
He pointed toward Rex.
"They came for the dog."
The door handle began turning.
Marcus stepped between the bed and the entrance.
"Nobody touches him."
The door opened.
A masked man stepped inside.
He looked at Marcus.
Then at Rex.
And spoke into a radio.
"Subject Four confirmed."
Marcus's eyes narrowed.
"Who are you?"
The man raised a small device.
A green light flashed.
Rex suddenly froze.
His ears flattened.
His body trembled.
Marcus looked at Elizabeth.
"What is that?"
She went pale.
"It's the original Sentinel command signal."
The masked man smiled.
"Good boy, Rex."
The German Shepherd slowly turned toward him.
Marcus tightened his grip on the leash.
But Rex was no longer looking at Marcus.
He was looking at the masked man.
And then, to everyone's horror, the dog took one step away from his handler.
End of Part 5.