EW 520 then W9 5378 at Barcelona
Cologne → Barcelona → London Luton
Timetable, Barcelona time
16:50EW 520 from Cologne at the gate
16:10W9 5378 to London Luton leaves the gate
23 h 20 apart on the timetable, overnight
W9 5378 leaves 23 h 20 after EW 520 arrives on the timetable: more than half a day, so not a connection we count.