The episode with Andante the racehorse. James diagnoses the horse as suffering from torsion of the bowel - an incurable and excruciatingly painful condition. The poor animal is in such agony that James euthanises it without further delay. But it's hard for James to have to put down such a beautiful animal, and he has a nagging fear that he misdiagnosed the horse. When Siegfried confirms James' diagnosis, James bursts into tears of relief and also sadness at what he had to do.
Mrs Pumphrey's anxiety about Tricky Woo at the vet is all too relatable for some pet owners. When the vets don't bring him out to meet her and are clearly bluffing to be reassuring, she assumes the worst and starts crying...Thankfully, it is Not What It Looks Like.
Poor Clive...
The story arc with Mrs Hall and her son, Edward:
Mrs Hall believes that Edward has never forgiven her for giving him in to the Police when he stole from her previous employer. So when Edward says he will visit her for Christmas - after all these years - she is hopeful and excited for a reconciliation. Every time someone rings the doorbell, Mrs Hall looks up expectantly. But Edward doesn't turn up.
The scene at the church from the same episode. Mrs Hall tries to sing with a Christmas carol but her voice falters as disappointment over Edward not coming to meet her overcomes her. Then Siegfried steps in to hold her hand and sing with her...turning it into a heartwarming scene.
When Mrs Hall and Edward finally meet in Season 3, Episode 5, it looks for a while that the meeting is going well. Then Edward's resentment about the stealing incident resurfaces. Mrs Hall holds her ground (despite her heart breaking at her son's anger) and says she could not have lied for him.
The goodbye scene between Mrs Hall and Edward at the railway station. Edward is going away with the Navy, and both of them are aware this may be the last time they see each other. But they haven't reconciled, and Mrs Hall runs after Edward trying to explain why she did what she did. Edward hugs her briefly and hops onto the train. Mrs Hall tries to hand him the box with his favourite childhood treats, but he drops it. Mrs Hall tries desperately to gather up the treats in the box again, as the train leaves. She thinks she sees Edward say something, but can't hear what it is and he is too far away for her to hear him repeat it... Then the station lady from earlier who's proficient at lipreading and sign language tells Mrs Hall that Edward said "I love you ma". Cue Tears of Joy from Mrs Hall, and Sand In My Eyes from the audience.
The whole scene is made even more tragic for modern viewers because Edward is wearing the cap of HMS Repulse, a battlecruiser sunk by the Japanese in 1941. Unless he is redeployed to another ship, there is a good chance Edward could be dead in a few years, and this might well be the last time Mrs Hall sees him.
The dying calves in Season 3, Episode 2... and the Break the Haughty arc with their owner.
When Siegfried lets drop in the middle of a dinner party, held to celebrate Tristan's (apparent) passing of his exams, that Tristan has in fact not qualified... poor Tristan is left struggling to come to grasps with his own failure combined with the heartbreak from his brother's (well-meaning) deception.
Siegfried's memories from World War I:
He saw a colleague give up his gas mask to save a horse from a chlorine attack, at the cost of the colleague's own life.
Then Siegfried and his fellow army vet, Maurice Oliver, were instructed by Major Sebright Saunders to put down all the horses because it wasn't cost-efficient to transport them back to England. Siegfried decided to follow orders because letting the horses escape would only result in a slower and more painful death for the animals from starvation.
Back in the present, Siegfried finds out that his old friend, Sgt Oliver, has recently killed himself - apparently having never recovered from the trauma of the War. Siegfried is badly shaken up, and obsesses over Sgt Oliver's last letter to him, wondering if there was some warning sign that he could have picked up and helped his old friend.
To make matters worse, Siegfried's current case involves one of Major Sebright Saunders' racehorses called River. River is suffering from trauma (Implied to be caused by being brutalised by a riding crop). Major Saunders doesn't want to be burdened with a racehorse which can't stand a riding crop, and wants the horse to be put down if it can't be made compliant. Thankfully, this storyline ends on a more positive note...
When Siegfried and Tristan finally have a heart-to-heart conversation about their relationship:
Siegfried divulges a bit more of his Tragic Backstory: Siegfried and his wife Evelyn had to take Tristan in at a young age after Siegfried and Tristan's parents died. Evelyn wanted Siegfried to have a child, but Siegfried wasn't ready for parenthood...until it was too late and Evelyn fell ill and died.
Siegfried tells Tristan that he's always cared for him, but part of Siegfried wishes he could have done things differently by Tristan, so that they would have enjoyed a closer relationship.
The official announcement of the start of World War II and Britain's entry into it. From Mrs Hall's stricken face, to Siegfried's quiet, stoic agony, to the obvious fear and nerves of Tristan, James, and Helen, the episode's title ("For Whom the Bell Tolls") is all too accurate.
