The devotion remained, but the desire had ebbed away, leaving a stale situation at Franklin’s Gardens.
Supporters would trudge to the ground more out of hope than expectation, and some decided to stay away for fear of suffering more misery.
Low crowds became a theme, with the December defeat to Ospreys in the Champions Cup the nadir.
Attendances had slipped away as the club went into reverse after topping the regular-season Premiership table in 2015.
Finishes of fifth, seventh and ninth were to follow, with the decline needing to be arrested ahead of what promised to be the most competitive season of them all.
London Irish had struggled and were sent down, to be replaced by an incredibly ambitious Bristol Bears side, steered by former Saints star Pat Lam.
It meant the summer was one of anticipation but also trepidation at Northampton, with fans unable to be sure what their side would produce in the following campaign.
Boyd’s arrival, along with new attack coach Sam Vesty and new scrum guru Matt Ferguson was, of course, greeted with optimism.
But with such little time for them to implement their ideas and a squad that had lost long-serving legends Stephen Myler, Christian Day and Ben Foden, among others, it really felt like it could go either way.
And that proved to be the case when the season started as Saints, unsurprisingly, struggled during the formative stages.
Heading towards Christmas, they were sitting perilously close to the bottom of the standings, placing immense pressure on their trip to Sixways to face Worcester Warriors.
Saints had suffered a late home defeat at the hands of another lowly side, Newcastle Falcons, earlier in the month, and tension was really cranking up.
It was becoming difficult to believe that things would turn around and that the cloud that had formed over Franklin’s Gardens would be lifted quickly enough.
But Boyd and his coaches somehow kept belief levels high, especially among an incredibly talented group of young players who refused to feel any sort of pressure.
They kept playing the way they were being taught by the new-look coaching team - and eventually Boyd’s chutzpah paid dividends.
He will have continually told his players that the good times would roll on a more consistent basis than just the odd strong performance, such as the one at home to Wasps in November.
And it wouldn’t be long until he was proved right as the eye-catching win at Worcester on December 21 proved the catalyst.
Table-topping Exeter Chiefs were conquered at Franklin’s Gardens in the final game of a tremendously turbulent 2018.
And though 2019 started with a stodgy defeat to Wasps, that was to become an anomalie rather than the norm as Saints really started to gather some speed.
They pushed Clermont Auvergne all the way in an incredible Challenge Cup clash at Stade Marcel Michelin, eventually being edged out 48-40.
And after eviscerating Timisoara Saracens in a win that was a version of rugby cruelty, they put 47 points past Leicester and 59 past Newcastle to book a Premiership Rugby Cup final place.
Back in the league, they produced one of the most comprehensive performances, if not the most, in the club’s recent history, smashing Sale Sharks 67-17.
Players such as George Furbank and Rory Hutchinson, two huge examples of the confidence that the youngsters had been injected with by the new coaches, were coming to the fore.
And the likes of Cobus Reinach, Dan Biggar and Taqele Naiyaravoro were starting to live up to their sizeable reputations.
There was still the odd speedbump in the road, with setbacks at Saracens and at home to Bristol Bears, but, again, that old word belief remained.
Saints bounced back to claim their first trophy since doing the double in 2014 as they finally smashed their Sarries hoodoo with a Premiership Rugby Cup final success at Franklin’s Gardens.
And the buzz that was felt around the ground that day showed just how far the club had come under Boyd.
The desire was back. It wasn’t just devotion that brought fans to the Gardens that day. It was an appetite to enjoy the attacking rugby that was now being played.
There was plenty of risk and plenty of reward, and Saints produced perhaps their most satisfying win of the season on the following weekend, marching to Welford Road and winning at the former fortress for the second time in two seasons.
Not only did they win, but they won with a swagger, with the likes of Reinach, Hutchinson and Tom Collins cutting Leicester Tigers apart.
Saints gave Clermont a fright in France on the following weekend before eventually bowing out of Europe at the quarter-final stage.
But hopes were still high that Boyd could steer his team to the knockout stages on all three fronts as optimism remained about a top-four finish.
A defeat to Gloucester put a spanner in the works, but Saints kept going, kept playing their way.
And after showing incredible steel to snatch a late success at play-off rivals Harlequins, they flew to a win at a Newcastle Falcons team who needed a victory to keep their slim hopes of survival alive.
Worcester, already safe, provided perfect opposition for the final home game of the season, allowing Saints to give an ideal send-off to the likes of Ken Pisi and Luther Burrell.
And eventually Boyd’s team booked their play-off place despite a final-day defeat at Exeter.
A return to Sandy Park last weekend was to prove to be just a step too far for a team whose journey felt like that of someone climbing Mount Everest.
And though the ending was not a fairytale one, with a flag stuck in the turf at Twickenham, the pictures taken at the summit were only positive ones.
The Saints players and coaches could still afford to smile and, crucially, so could their supporters.
Because after a few years when it felt like the team bus was going backwards, it is now very much moving up the gears.
One trophy has already been secured in a season of stark progress.
And although there is still so much work to do to bridge the gap to England and Europe’s elite, at least Saints are now mixing it with them again.
And for that, a huge thanks has to go to Boyd and everyone else at the Gardens who has played a part in turning one of the country’s biggest rugby clubs around.