Scotland's unlikely victory over Ireland last Sunday was a major leap forward for them. Not only did it make history - their first back-to-back wins ever in the Six Nations - but it may also go a long way to shaping their future.
After the frills of Hogg, Visser, Maitland and co providing the style, this was the gutsy, bodies on the line performance that cemented the substance. Ireland had over 70 per cent possession and territory; they made clean breaks and beat countless defenders; they had to make just 42 tackles, as supposed to Scotland's 154 - yet they scored only eight points.
At international level, that is extraordinary.
You could point to missed kicks at goal if you wanted, but there's no denying how hungry, tenacious and relentless that Scotland team was.
I watched it and saw many parallels with Saracens. Defence is not just about the individual tackles; it's about having the hunger to bust a gut to get round the corner of the ruck, and then the continued focus and energy to maintain good line speed. Pure physical fitness isn't enough - it has to come from your own hunger and your trust in your team mates' hunger.
The Sarries on-field watch words - discipline, honesty, work rate, humility - capture that. It's the cornerstone of our success in the last three years.
And unsurprisingly, the man who stood out on Sunday is the same man who's part of both teams: captain Kelly Brown.
He made more tackles than anyone else, with 20. And if I had the stats I'd be willing to bet he was involved in more breakdowns than anyone else too.
The sight of him, covered in blood, lifting whatever trophy they've come up with this time, was pretty special.
But anyone who follows Sarries shouldn't be that surprised. Along with our own captain Steve Borthwick, he is our most consistent player. High tackle count, very low missed tackle count, good hands, high turnover count, heavy-duty carries into the heart of the defence, hitting rucks - you name it.
In the 2011 Premiership Final, for example, he made 26 tackles - ten of which were in the nine minutes of add-on time where we couldn't afford to cede an inch. And he made the final, match-winning turnover.
For all the flash of Goode, Ashton, Brits, Tomkins et al, we rely on the likes of Brown to glue everything together, to do the stuff which is unpleasant, and rarely gets any praise - even with your lungs bursting.
Off the pitch though, Kelly is the least ferocious, most humble and quietly spoken guy around.
He gets a lot of attention from journalists not just as national captain, but also because he has always suffered from a stammer which inhibits his public speech. His story of overcoming that stammer, through training and by taking up singing (great voice!), is as likeable and respectable as the man himself.
The Lions plane awaits.