Former Hartlepool United loan defender Adam Jackson has left Middlesbrough to join Barnsley.
The centre-back spent much of last season at Pools, where he was a revelation at the heart of the defence, alongside Matthew Bates.
Pools boss Craig Hignett had hoped to bring the 22-year-old back to the Northern Gas & Power Stadium this season before turning his attention to Toto Nsiala, who joined the club from Grimsby Town.
But now Jackson has signed a three-year deal for the Championship high-fliers after the clubs agreed an undisclosed fee.
A graduate of the Boro academy, the Darlington-born defender failed to make a senior competitive appearance for the Riverside outfit.
But Aitor Karanka sent the ex-England Under-19 international to Pools, where he played 35 times in the league and cup.
Fresh from an excellent run in the Pools side, Jackson played throughout the early stages of Boro's pre-season programme, including the club's stint in Spain.
And while he did not make the cut for the Premier League, the Tykes have clearly seen something they like for their first season back in English football's second tier.
"He is ready for the challenge of the Championship," said Barnsley head coach Paul Heckingbottom, who br Pools left-back.
"His ball distribution, speed, and ability to bring the ball out from the back fits perfectly into our playing style."
Jackson will fill the gap left at Oakwell by Alfie Mawson's imminent move to Swansea City.