BA 484 then QR 3655 at Barcelona
London Heathrow → Barcelona → Valletta
Timetable, Barcelona time
16:00BA 484 from London Heathrow at the gatealso IB 3665, LA 5487, AA 6728, QR 8316, VY 9657
11:25QR 3655 to Valletta leaves the gatealso IB 5118, LL 5118
19 h 25 apart on the timetable, overnight
QR 3655 leaves 19 h 25 after BA 484 arrives on the timetable: more than half a day, so not a connection we count.