Luton Town have brought Matthew Spring back to Kenilworth Road after paying local rivals Watford a fee of £200,000.
The midfielder, who made 289 appearances for The Hatters after joining as a trainee, has signed a two-and-a-half year deal to return to the Championship side.
Spring has spent the last year-and-a-half at Vicarage Road after signing from Leeds, but found first team chances hard to come by following The Hornets' promotion to the Premiership.
After making just six league appearances this season, Spring has now sealed a return to the club that nurtured him in the early years of his career.
The signing of Spring represents a huge boost for Mike Newell's side after the departure of key figures Rowan Vine and Carlos Edwards in January.
Watford have received a fee of £200,000, which could rise to £300,000 dependent on future success, and Hornets boss Adrian Boothroyd has wished Spring well as he returns to the club's bitter rivals.
"I'd like thank him for the part he played in helping secure promotion last season," Boothroyd told the club's official website.
"Sometimes players leave clubs with bad feeling, but that's certainly not the case here.
"I think Matthew was brilliant for us and we'd like to wish him and his family well for the future."