In shortA hook is a certain promise plus an uncertain process. In the first five seconds show a concrete image that promises the kind of satisfaction the series will deliver; in the next twenty-five, land three escalating blows on the lead's identity so the viewer is certain payback is coming and only curious how. Mystery without a promise is not a hook.

Viewers do not stay because they wonder what will happen. They stay because they already know what kind of thing will happen and want to see how. The strongest openings in the format make a promise the viewer is sure of, then withhold only the method.
Hook = a promise the viewer is certain of + a process they cannot predict.
"Will she get revenge?" is a weak hook: the viewer may not care yet. "She has walked back into the house of the man who buried her, wearing a face he does not recognise, and he has just caught her scent" is a strong one. Revenge is certain. How she survives the next minute is not.
The first shot is watched with the sound off by a large share of the audience. It has to be an image that carries the promise on its own: a hand turning a wedding ring inward, a coffin lid with a scratch on the inside, a contract with a fresh signature next to an old one. Faces talking to camera are not images; they are sound.
Do not open on the setting. Nobody stays for an establishing shot of a mansion.
The rest of the opening is an attack on the lead's identity in three steps, each worse than the last and each aimed at a different part of who they are.
Each blow is a promise: if she is humiliated, then we expect the counterstrike; if the accusation is unjust, then we expect justice; if she is silenced, then we expect the moment she speaks. The viewer is now certain what the series is for.
The blows should be specific to what the lead is. A surgeon is attacked on her hands, a Luna on her scent, a socialite on her marketability. Generic cruelty ("you're nothing") does not attach to anything and does not generate expectation.
At about second 25 the lead does one small thing that proves the promise is real: a smile at the wrong moment, a name said too calmly, a document produced from a bag. Not the counterstrike itself; the evidence that a counterstrike is coming. This is the difference between a lead who is pitiable and a lead who is patient.
The format has a few openings that feel like hooks and are not. Each shows something unknown without anything certain.
The opening can go as low as the finale goes high. A lead who is only mildly inconvenienced in the first thirty seconds has a series with a low ceiling. Press as hard as the platform's rules allow, in the first minute, on the thing the lead cares about most; the rest of the season is the distance back up.
The Alpha's Dead Bride, episode 1: a woman in a wedding dress is left at the altar and driven off a mountain pass; the first frame after the title card is five years later, a different face, the same ring turned inward. Blow one: the Blackwood family does not recognise her and dismisses the "medical investor" as a nobody. Blow two: her offer is called an insult. Blow three: the Alpha himself sends her away in front of the pack. At second 28 he stops, because he has caught a scent. The promise (she will take the pack apart) is certain from the ring; the process (how, with that face, from inside) is not. The episode's own cliffhanger then converts his recognition into the question the next episode answers.
On Dawnwood the writing is free: type a premise, get a season bible and every episode script, revise them as much as you like. Credits are only spent when you generate art or render video, and every charge is shown before you confirm.
Start a series freeHow a series gets made →