The train was gathering steam but no one saw it hurtling down the tracks towards Liverpool Football Club. As Tony Cottee scored two late goals to help Everton hold their Merseyside rivals to a 4-4 draw after extra-time in a fifth-round FA Cup replay at Goodison Park, the sole topic of conversation was how an extraordinary run of games between the old adversaries (a league match had preceded the initial Cup meeting) might end in the next meeting.

It was late February 1991. The stress Kenny Dalglish had been internalising for far too long was about to prompt his resignation but, as the teams trooped off, players and fans remained in blissful ignorance of the visiting manager's mindset.

Two days later Dalglish was gone. The immense strain occasioned first by Heysel and then Hillsborough had finally told on a man who continues to offer the victims' families his enduring support. Now, 20 years later, he is returning home for his first game back at Anfield since taking over from Roy Hodgson, and finds himself facing the club that persuaded him it was time to walk away.

Earlier in the month it had all seemed business as usual in derby No1 as a goal from Jan Molby and two from David Speedie undid Everton 3-1 at Anfield. Then came a goalless draw in the original cup match, closely followed by that 4-4 thriller.

By the third instalment of this saga, Ray Houghton, then returning from injury, was a Liverpool substitute. Sitting on the bench the midfielder found himself well placed, late in the game, to see Dalglish resting an arm on the dugout roof as a look of abject, almost bewildered, resignation set in across his face.

It made a great photograph and that oft reproduced pose would subsequently prove the subject of considerable amateur psychoanalysis. At the time Liverpool's players thought their invariably inscrutable manager was confounded by kamikaze defending. "I had no idea whatsoever about what was to come and neither did anyone else, not even those who knew Kenny best," Houghton says. "Ask Alan Hansen, he was his closest friend and he didn't have a clue. Kenny's resignation came totally out of the blue; you could have knocked each and everyone of the Liverpool players down with a feather.

"In the dressing room after the 4-4 with Everton no one had an inkling of what was to follow. Kenny was quiet afterwards but he was quite often quiet – and, although we'd played very well, we had some dreadful defensive lapses. I got the impression he was pleased yet extremely disappointed."

Mixed feelings often indicate ambivalence but Dalglish is not a shoulder-shrugging shades of grey man. "Kenny takes responsibility for people," Houghton says. "He always really cared about the cleaners and tea ladies at Liverpool."

Dalglish's extraordinary sense of loyalty often exceeds the customary calls of duty. "Kenny's son, Paul, lives in America now but if he phoned and said: 'My car's broken down', Kenny would be straight on to the breakdown services in Arizona organising a pick-up," Houghton says. "But he won't just go out of his way for family; he gave so much to relatives of the Hillsborough victims and, eventually, it took its toll.

"Perhaps because as players we'd all been through Hillsborough and because we were young and wrapped up in ourselves we didn't properly consider just how much Kenny had taken on and how it might be affecting him. He seemed fine on the outside."

If the final act of Dalglish's first managerial Anfield reign did not end with a win at Goodison Park, at least it is now regarded as one of the best Merseyside derbies. "I couldn't believe what was unfolding in front of me," Houghton says. "That game had everything, it ebbed and flowed, the challenges were really flying in hard, and some very good play was undermined by bad mistakes at the back. I remember Glenn Hysen playing 'after you' with Bruce Grobbelaar.

"My overriding memory, though, is seeing John Barnes curl a sensational goal into the top corner. Afterwards our mood was: 'How did we not win that? How did we lose control?'"

Peter Beardsley silenced Goodison by opening the scoring with a half-volley before Graeme Sharp headed an equaliser. Back came the visitors courtesy of Beardsley's double shimmy and a left-foot, 25-yard shot. Sharp levelled again, then a rare Ian Rush header nudged Dalglish's men in front.

Cue the late substitute Cottee and a typical sidefoot to make it 3-3 after 90 minutes. Next Barnes reminded everyone his less celebrated right foot was pretty decent, too, sending a superlative curler imperiously beyond Neville Southall before another Cottee sidefoot forced a second replay.

"The details of the game are a bit of a blur now but I do remember that, afterwards, there was absolutely no suggestion Kenny Dalglish was about to quit," Southall recalls. "When the news came out, everyone at Everton was massively shocked."

No one guessed that Barnes's goal represented a watershed moment. "After we took the lead for the final time I knew I had to make a change to shore things up at the back," said Dalglish, some years later. "I could see what needed to be done and what would happen if I didn't. I didn't act on it. That was the moment I knew I was shattered. I needed to get away from the pressure."