EC 3749 then IB 5410 at Barcelona
Milan → Barcelona → London Gatwick
Timetable, Barcelona time
21:30EC 3749 from Milan at the gate
13:55IB 5410 to London Gatwick leaves the gatealso LL 5410, VY 7614
16 h 25 apart on the timetable, overnight
IB 5410 leaves 16 h 25 after EC 3749 arrives on the timetable: more than half a day, so not a connection we count.