EI 159 then FR 3977 at Dublin
London Heathrow → Dublin → Barcelona
Timetable, Dublin time
13:35EI 159 from London Heathrow at the gate
07:40FR 3977 to Barcelona leaves the gate
18 h 05 apart on the timetable, overnight
FR 3977 leaves 18 h 05 after EI 159 arrives on the timetable: more than half a day, so not a connection we count.