The Walking Dead delivers a bloody beatdown with the ferocious "Stalker". Episode ten has Beta (Ryan Hurst) infiltrating Alexandria with ease. But his efforts to capture Gamma, now Mary (Thora Birch), doesn't go as planned. Father Gabriel (Seth Gilliam) is itching for a fight with the Whisperers, much to the consternation of Rosita (Christian Serratos). Daryl (Norman Reedus) gets his fight on with (Alpha). They both suffer the consequences. Lydia (Cassady McClincy) reappears at a crucial moment.

"Stalker" opens with Beta crossing a field to an RV. The Whisperers inside lift up a chair, which leads to a dark tunnel. That night, Rosita has a nightmare. Beta is standing over baby Coco's crib with a knife. She and Father Gabriel wake up to find Gamma at the gate. Surrounded by fighters, she tells them about the horde at the cave. Their friends are in trouble. She is the aunt of the baby left at the Hilltop. She wants to see her nephew. Father Gabriel doesn't believe her. Rosita punches her out cold.

In the woods, Daryl follows a Whisperer to the entrance of the cave. He watches as Alpha and several others lead a group of walkers out. Gamma wakes up on the floor of the cell. Rosita and Father Gabriel warn her of what happened to Dante. Gamma knew nothing of the spy. She breaks down and admits to killing her sister.

At the river, Daryl ambushes Alpha's group. He shoots a Whisperer with an arrow; who is then feasted on by the dead. He tears out of the woods, stabbing and killing two more. He knocks away Alpha's shotgun, then wounds her shoulder. But she slices him across the forehead. He's blinded as blood pours into his eyes. Daryl grabs a branch and smashes Alpha. She falls into the dirt. He viciously jams the wood into her wounded shoulder. Screaming, "Where are they!"

He lets up to face incoming walkers. Still blinded, he swings wildly. Alpha grabs her knife and plunges it into his thigh. He reels in pain, but can see her struggling to pick up the shotgun. Daryl limps away to escape.

Gamma is brought before the Alexandria council. She shows them the cave on the map. Father Gabriel orders her taken back to the cell. He wants to mount a rescue. Show the Whisperers they're not afraid, "Take one alive. Start pulling teeth and fingers." Rosita is dismayed.

A wounded Alpha trudges to a derelict gas station. She sees signs of blood. Inside, Daryl hides behind the counter. The knife is still in his thigh. Alpha collapses on a set of tires at the door. She painfully beats her gun on the door; attracting walkers from the woods.

In their home, Rosita and Father Gabriel gear up. He wants her to stay and defend Alexandria. She's worried about him outside without her. Coco has already lost one father. At the cell, Judith calls Gamma from the window, "What's your name?" Gamma's name is Mary. She and her sister were from Santa Monica, California. She admits forgetting her past. That is what Alpha does to you. "You don't look like a monster to me," Judith replies.

At the garage, Alpha keeps clanking. Three gnarly walkers come in. They growl at her, but go towards Daryl. He kills two with a tire iron. Then pulls the knife out of his leg to kill the other. Blood spurts out.

At the Alexandria gate, Echo watch post reports walkers incoming, then goes silent. Father Gabriel splits up fighters to attack them on the road. He decides Rosita and Laura (Lindsley Register) will stay behind to guard the gates. Rosita appreciates the call. He kisses her gently, then gives her his hat, "I will see you soon."

That night, Beta climbs out of the dirt at Dante's grave. He goes to a couple of houses and kills the Alexandrians inside. He kneels on the floor, waiting for them to come back. On the road, Father Gabriel's team sees their post people dead, but no sign of the walker herd. In the house, the dead come back to life. Rosita sees them on the street. She radios back to Father Gabriel, he realizes they've been duped.

Beta kills the prison guard and goes after Mary. She's not afraid of him. She doesn't believe Alpha will make her death painless. Laura gets the drop on Beta, but he slams her into the cell bars. Mary runs outside screaming for help. She hides in the house above. Beta stalks up the stairs, but is shot through a room door by Judith. Mary yells for Judith and RJ to escape. Beta gets up, he's wearing metal body armor. Rosita attacks with her club. She gets a few hits in, but is overpowered. Just when he's about to stab her, Mary appears with a knife to her throat.

Mary leads Beta down the dark road. She knew Alpha wanted her alive. Gunshots ring out. Beta runs into the woods. Mary had taken him to Father Gabriel's group. He points his gun at her. She swears, "I didn't betray you."

In the garage, Alpha rips off her mask. She and Daryl are both severely wounded. She "thanks him" for making her strong, for the "pain." She becomes enraged when Daryl says she didn't "love Lydia." She stumbles up in fury. Alpha crawls towards him, but passes out.

The next morning, she awakens to find Lydia standing above her. Alpha puts a knife to her chest, but Lydia doesn't stab her. Alpha sings as Lydia soothes her wounded mother. But she did not come for her. Alpha wakes up again further in the day. Lydia has gone, and rescued Daryl. She weakly stands up. Her knife stuck in the table with an etched note, "Your way is not the only way."

In Alexandria, Aaron (Ross Marquand) has returned with the cave survivors. Father Gabriel shows him how Beta entered the walls from the grave. The Whisperers sealed the tunnel below. Rosita leads a caravan to the Hilltop. Mary, Gracie, Judith, and the children will go with them. Baby Coco will stay with Father Gabriel. She's safest with him.

In the woods, Daryl wakes up to see Lydia. She had been watching both groups for some time. "Did you kill her?" "If it was your father, could you have?" In the garage, Alpha is found by her followers. She is stronger than ever. "Our horde will butcher and consume them," she starts to sing and chant. "This is the end of the world. We are the end of the world."

"Stalker" encompassed the good and bad of the show. The visceral fights, Daryl vs. Alpha, Beta vs. Alexandrians, were damned entertaining. But the story is again filled with contrivances. The ease at which the Whisperers break into Alexandria is laughable. Beta could have burned the whole place to the ground and ended the war. Alpha and Daryl in the garage become supremely foolish. She was strong enough to track him there, but couldn't walk ten feet to finish the job? Even though she has a shotgun. Crank up willing suspension of disbelief for the zombie apocalypse. The Walking Dead returns next week with "Morning Star," on AMC.