Deadlock Nurse Harrow Guide: Every Ability, Leech Stacks, Best Upgrades and How to Counter Her

Nurse Harrow is the final hero of Deadlock’s City Never Sleeps update, and she plays unlike anyone else in the roster. She heals by shooting her allies with syringes, grows stronger every time she collects a leech from an enemy, can make a teammate shrug off damage for a few seconds and ends fights by terrifying anyone who looks at her. This Deadlock Nurse Harrow guide explains every ability and upgrade, how her leech stacks work, which upgrades to take first, how to play her and how to counter her when she is on the other team.

Who Is Nurse Harrow in Deadlock?

Nurse Harrow joined Deadlock on October 20, 2026, as the sixth and last hero of the City Never Sleeps hero vote. She is a support hero who mixes healing with draining damage, and her signature mechanic is collecting leeches from enemy heroes for permanent regen and fire rate.

Valve introduced her as a nurse from the Marble Hill Possession Ward whose methods may seem unorthodox, but work. In its release post, Valve also revealed that over 110 million votes were cast during the City Never Sleeps event and that 22,194 players voted exclusively for Harrow. Her weapon is called Code Blue, a rapid-fire gun with an 11-round magazine, and she starts with 730 health.

Nurse Harrow Abilities Explained

Harrow’s kit has four abilities. The values below are base values from the current game build as listed on the community Deadlock wiki, which reads them from the game files. Valve has not published a full ability sheet itself.

• Leech Therapy (1): Throws a jar of leeches that attach to enemies, dealing spirit damage over time and eating away at the duration of their buffs. Once a leech on an enemy hero has finished feeding, it crawls off and Harrow can pick it up. Each collected leech heals her for the health it drained and permanently grants 0.6 health regen and 5% fire rate. The cooldown is 30 seconds.
• Wretched Vapors (2): Releases a vapor on Harrow herself or an ally. During the Specter Rush, all actions speed up by 25% and incoming damage is numbed and stored as looming specters. When the vapors wear off, the Specter Crash slows all actions by 20% and the remaining specters deal their delayed damage plus 30% extra. Any healing the target receives removes specters first, so healing a boosted ally prevents that damage. The rush lasts 4 seconds and the cooldown is 40 seconds.
• Healing Needles (3): Loads Harrow’s weapon with a full clip of syringes that heal allies for 25 health per shot, with a 15% bonus on headshots. It uses charges: dealing damage to enemies recovers them, and every collected leech slowly restores them too. Reloading spends a charge for a fresh clip, and unused syringes are refunded as a partial charge when you put them away.
• Lurking Terrors (4, ultimate): Harrow opens her bag and channels spirit damage at enemies in front of her. Enemies looking at her build up terror and cannot use stamina or movement abilities, and at max terror they flee from her in fear. Each collected leech adds 0.1 seconds of fear duration. Enemies facing away take only 50% damage unless they are feared. The cooldown is 200 seconds.

How Nurse Harrow’s Leech Stacks Work

Leeches are the core of every Nurse Harrow match, because they make her stronger for the rest of the game and also feed her other abilities. Here is how they work:

1. Land the jar on enemy heroes. Leeches can also attach to troopers and Haunts, but only leeches that fed on heroes can be collected.
2. Wait for them to finish feeding. After that, the leeches crawl back toward Harrow. If the enemy hero dies while a leech is still attached, you can pick that leech up early.
3. Pick them up. Collectable leeches are marked with a red leech icon that Harrow can see across the map and through walls. According to the wiki, they despawn after three minutes, so you don’t need to grab them in the middle of a fight.
4. Stack them. You can hold up to 10 leeches at base, or 18 with the third Leech Therapy upgrade. Each one adds regen, fire rate, Healing Needles charge over time and fear duration on Lurking Terrors.
5. Don’t throw them away. The ability text says Harrow loses 25% of her leech stacks when she dies. In practice it is rounded to whole leeches: according to the wiki, she loses 1 leech at 1 to 5 stacks, 2 at 6 to 10, 3 at 11 to 13 and 4 at 14 to 18. Either way, a careless death costs you long-term power, not just time.

Nurse Harrow was the final hero added in Deadlock’s City Never Sleeps update.

Every Nurse Harrow Ability Upgrade

Like every Deadlock hero, Harrow has three upgrade tiers per ability. This is what each one does in the current build:

• Leech Therapy: Tier 1 makes leeches drain stamina and restore it to you on pickup. Tier 2 cuts the cooldown by 10 seconds and adds 4 Spirit Power per leech. Tier 3 adds 1m radius, more spirit scaling and 8 extra max leech stacks.
• Wretched Vapors: Tier 1 cuts the cooldown by 15 seconds and adds 7m cast range. Tier 2 adds 1 second of duration and 20% healing effectiveness. Tier 3 adds 15% rush speed and dispels non-ultimate debuffs.
• Healing Needles: Tier 1 adds one max charge. Tier 2 adds 20 heal per shot and makes shots restore stamina. Tier 3 adds spirit scaling and makes shots extend allies’ non-ultimate buff durations by 6%, up to their maximum.
• Lurking Terrors: Tier 1 cuts the cooldown by 50 seconds. Tier 2 strengthens the move speed and fire rate slow and adds 30 damage per second. Tier 3 adds 3 seconds of channel time, more spirit scaling and makes Harrow immune to damage while channeling.

Best Nurse Harrow Upgrade Order

Harrow is only a week old and the community is still settling on a standard build, so treat this as our recommended starting point rather than a fixed meta:

1. Unlock Leech Therapy first. Every leech you collect early pays off for the whole match, so start stacking in lane right away.
2. Unlock Healing Needles and Wretched Vapors next. Needles gives you real sustain for your lane partner, Vapors lets you save an ally from a gank.
3. Unlock Lurking Terrors as soon as it is available. It is your main teamfight tool.
4. Prioritize Leech Therapy Tier 2. The shorter cooldown means more jars, more leeches and more Spirit Power per leech.
5. Then Lurking Terrors Tier 1. Cutting a 200 second ultimate to 150 seconds means you get it for far more fights.
6. Fill the rest based on your team. Take Healing Needles upgrades if you have frontliners that need healing, Wretched Vapors upgrades if you keep saving a carry, and Leech Therapy Tier 3 once you are close to 10 stacks.

How to Play Nurse Harrow: Tips

• Keep shooting enemies. Healing Needles charges come back from damage you deal, with headshots and melee hits recovering much more than body shots. A Harrow who only heals runs out of syringes quickly.
• Collect leeches only when it is safe. They stay on the map for a while and you can see them through walls, so finish the fight first instead of walking into the enemy team for one stack.
• Plan the crash. Wretched Vapors only delays damage. When the rush ends, the target takes the stored damage plus 30% and is slowed. Use it to let an ally finish a kill or escape, and then heal them with Healing Needles so the specters disappear before they hit.
• Use Vapors on yourself too. The ability works on Harrow as well, which can help you survive a dive long enough to escape.
• Cast Lurking Terrors where enemies have to look at you. Terror only builds on enemies facing you, and anyone looking away takes half damage unless feared. Walking into the middle of a fight and opening the bag works much better than casting from behind.
• Try weapon items on your syringes. According to the wiki, Split Shot fires several healing syringes, Ricochet bounces them to nearby allies for half the base heal, and Armor Piercer lets them pierce through allies for the full heal.

How to Counter Nurse Harrow

• Buy Healbane. The Tier 2 Vitality item makes your spirit damage reduce the enemy’s incoming healing, which hurts both Harrow’s syringes and her Vapors target. Even the game’s own announcer voice lines tell players to buy it against a Harrow on a killstreak.
• Look away from Lurking Terrors. Terror only builds while you face her, so turning away keeps you out of fear and stops the stamina and movement lock. You still take half damage, so leave the cone if you can.
• Punish the crash. When an enemy’s Wretched Vapors runs out, they take their stored damage plus 30% and move slower. Save your burst for that moment.
• Kill her early and often. Every death costs Harrow roughly a quarter of her leech stacks, so focusing her keeps her from snowballing.
• Use Unstoppable and debuff resist. According to the wiki, Unstoppable suppresses the fear from Lurking Terrors and Debuff Resist shortens it. Warden’s Last Stand has made him immune to the fear since a fix on October 21.

Deadlock Nurse Harrow: Our Verdict

Nurse Harrow rewards patient players who keep shooting, collect leeches safely and time their Wretched Vapors around the crash. Stack leeches early, heal your frontline with Healing Needles and save Lurking Terrors for the moment the enemy team groups up in front of you. New to the latest Deadlock update? Read our overview of the City Never Sleeps update and our Deadlock Haunts guide. This guide reflects Deadlock after Nurse Harrow’s release on October 20, 2026, and the small fixes of October 22. Deadlock is still in early development, and Valve regularly rebalances new heroes, so values may change with future patches.

Nurse Harrow FAQ

When was Nurse Harrow released in Deadlock?
Nurse Harrow was released on October 20, 2026, as the final hero of the City Never Sleeps update.

How many leeches can Nurse Harrow stack?
She can hold 10 leech stacks at base and 18 with the third Leech Therapy upgrade. She loses roughly a quarter of her stacks on death, rounded to whole leeches.

Can Nurse Harrow use Wretched Vapors on herself?
Yes. The ability can target Harrow or an ally.

What is the best counter to Nurse Harrow?
Healbane to reduce her healing, turning away from Lurking Terrors, burst damage on targets when their Wretched Vapors crash and focusing Harrow herself so she loses leech stacks.

Keep the adventure going! Check out more Gaming Guides on Gamersuniverse.

Picture Source: Valve