What on Earth is Straker's motivation?

He has superhuman powers
And if he proves to be a good servant he will get to live for eternity.

This sums it up pretty well, I think.

Servants of Vampires (according to lore) are called "Ghouls". They are basically 20% Vampires, with slight strength increase to help them do the deeds of their masters, even though they are mostly human.

So Ghouls are also bitten and turned, then there is no going back (just like all the people bitten in the town). Slaves for eternity.

In ancient Arabian folklore, the ghūl (Arabic) dwells in burial grounds and other uninhabited places. The ghul is a fiendish type of jinni believed to be sired by Iblis.[6]

A ghoul is also a desert-dwelling, shapeshifting, demon that can assume the guise of an animal, especially a hyena. It lures unwary people into the desert wastes or abandoned places to slay and devour them. The creature also preys on young children, drinks blood, steals coins, and eats the dead,[7] then taking the form of the person most recently eaten.

"Servants of Vampires (according to lore) are called "Ghouls". They are basically 20% Vampires, with slight strength increase to help them do the deeds of their masters, even though they are mostly human."

Complete nonsense. Servants of Vampires are called "familiars" and while they are under the command of the vamp they serve, they're not ghouls. A ghoul is an undead creature mostly associated with Arabic folklore who preys on the dead. Please kill yourself - we don't need any more stupid people out here.

That's very well said 'Vestdennis'!

O.k., 'Hollankreil' raised a good question 'What on Earth was Straker's motivation.'

I have to say that 'Jrdragon40' gave a worthwhile and succinct answer as follows:'He is under Barlow's control, to a degree, but also acts as a faithful servant for an implied promise of eternal life for his efforts.'

I am not sure that I will be able to improve on that as an answer but might be able to provide an extended piece of dialogue that hints in the same direction.

The 2005 (Illustrated Edition) of 'Salem's Lot' contains extended scenes and dialogue which were in the first draft of the novel, but left out of the final (published) draft.

One of the extended scenes is as follows:

***

From 'Salem's Lot' (2005 Illustrated Edition) by Stephen King:

In the original ending to Susan (II) , Count Barlow (who is called Sarlinov in the original manuscript) and Straker meet out near the end of town to discuss how the novel’s heroes had been faring.

The Deep Cut Road skirts the marshes to the southwest of the town’s center, and then winds crazily through a series of folded ridges and sudden, knife-cut dips, and here the country was so wild that even the ubiquitous trailers were left behind. It was here that the big fire of 1951 burned at its most feverish, destructive pitch, and the growth has come back and formed into fervid tangles and nightmare patterns which lurch over and under huge deadfalls like a drunkard’s stagger. This country continues for only five miles or so, but it is five miles of the wildest land in the area. Now, with much of the fall foliage dashed from the trees and the wildly-leaning trunks painted by the moonlight, the woods looked like nothing so much as a three-dimensional maze constructed by a madman.

At nearly midnight on that Friday night, a black Packard – either a ’39 or a ’40 – was parked somewhere along this stretch of road, idling quietly. The exhaust drew a wavering line in the dark. A tall shadow – Straker – stood with one foot on the driver’s side running board, smoking one of his Turkish cigarettes.

Something stirred in the air, darker even than the pines that formed the scene’s backdrop. A large crow, or perhaps a bat. Its form seemed to shift, elongate, and change. For a moment it seemed oddly insubstantial, as if it might disappear altogether. And then there was a second shadow, standing beside the first.

‘Our father has been kind,’ Straker remarked.

‘Be it ever so,’ remarked the other. His hair was now a vigorous black, with the faintest speckles of gray at the temples. ‘Mr Ben Mears?’

‘In the hospital.’

‘And Mr Tibbits?’

‘In the constable’s lock-up. Mr Bush will attend to him later.’

‘Burke is out of the way?’

‘Yes. Not dead, but also in the hospital. He had a heart attack.’

‘It is sufficient. He had the most knowledge; and a certain . . . persuasiveness.’

‘But no zealotry.’

‘Ah, no.’ The figure with the vigorous black hair laughed softly. He did not in the least look like Bela Lugosi or Christopher Lee. ‘No zealotry there.’

‘Is Master Glick—’

‘Master Glick is about his business. Yes. Yes, indeed.’ The dark man laughed again.

Straker asked humbly: ‘Is it my time yet?’

‘Almost, my good servant. It is almost time.’

‘Our father is kind,’ Straker said, and there was the faintest touch of resignation in his voice.

‘Be it ever so.’

Together, in the darkness, they seemed to merge into a single shadow.

***

The dialogue at the end of the passage: 'Is is my time yet?' seems to give a hint in the direction that 'Jrdragon40' had suggested, but please post with your own thoughts.

I think if david soul shot him once, or even twice, maybe straker would have been ok, but he shot him like 5 times, and clearly theres only a limit to his power. I remember getting a bit freaked out when straker just sorta waltzed out and grabbed the guy like he was a doll, so clearly straker had some kinda superhuman strength and power that he clearly enjoyed as the barlows servant. but perhaps no one had attempted to actually confront him and shoot him down that many times before. I don't think he was under the vampires control, he came off as a man who enjoyed what he was doing and reaped the benefits of being barlows servant.

Gary's good people though.

Don't you talk bad about gary overman on this here blog!