After the 2006 season finale, Kim's life would never be the same again. Not only had he just got married to Rachel, but Kit turned up on his doorstep with news that he didn't think he'd be hearing in quite a while. He was going to be a dad. Rachel found out soon enough and was shocked at the situation. After some calming words from Kim, they told each other that they would find a way to get through it. But they didn't know how hard it was really going to be.
Things were going fairly well, Kim was trying to balance his time between Rachel and Kit but Rachel started to feel as though Kim was overcompensating by doing things for her rather than talking about the baby. Kim agreed to be more open with her. Of course, that started with him not telling her that Kit was at the hospital having an ultrasound. After Tony blurted it out that Kit was having an ultrasound that afternoon, Rachel told Kim that he should go, as it was moments like that, that he wouldn't want to miss. 
After a cliff hanging experience A.K.A Kit and Rachel's car crash, Kim and Rachel had another argument. Kim blamed her for causing Kit's migraine, which was the reason she needed to go to the hospital in the first place.
When James' Dolton arrived in town, after accepting a short term position as a nurse at the NDH, Kim and Rachel's life wasn't about to get any less crazy. James and Kit were together for a while back in the city and got back together when he arrived back in the Bay. That meant that Kim could spent more time with Rachel, as James would be able to look after Kit more. That plan was to work until James held Kit hostage in her own house. James was taken to hospital, although he didn't stay there long as he discharged himself not long after. It turned out that he had gone to Kim and Rachel's place.
Kim returned home to find James in his house. He explained why he left the hospital and Kim reluctantly drove James's to the bus stop. When Rachel found out, she was not happy. After a huge argument, Kim went to speak to Kit and Hugh was a listening ear to Rachel. That was just the start of their marriage breakdown.
The arrival of Archie put a huge strain on Kim and Rachel's already fragile marriage, and thing's weren't about to get any easier for them. Hugh Sullivan had arrived shortly before Archie was born and things seemed unusually tense between him and Rachel. 
With the death of Beth, Kit needed more help with Archie which meant that Kim usually spent more time with them than Rachel. Rachel tried to cope and often spoke to Hugh about how she was feeling. 
Hugh and Rachel went to a conference together and Rachel (a very drunk Rachel!) asked Hugh why they didn't get back together ages ago. Hugh was feeling very awkward by that stage and Rachel had practically fallen asleep! While Rachel was there, Kim was with Kit. Kit was feeling like she wasn't a good mother so Kim tried to comfort her and they ended up kissing. Kim asked her why it happened and she said it was because she was stressed. They both agreed that it didn't mean anything and tried to move on. 
Hugh moved in with Kim and Rachel for a while and that's when things got particularly 'weird' between him and Rachel. He decided to move out, which surprised Rachel. She asked him why he wanted to leave and he explained that things had been getting pretty intense around the place. Rachel was still none the wiser as to why he had left though.
Another shock for Kim and Rachel was when Kim was electrocuted! He started to have flashbacks in which he saw Kit but not Rachel. Kim didn't know why and Alf tried to reassure him that it didn't mean anything, but Kim wasn't to sure.
The truth about why Hugh was being so distant soon became apparent though. After another huge argument with Kim, Rachel went to speak to Hugh which was when he admitted he was in love with her! Rachel didn't know what to say apart from that they were just friends and nothing more. 
Kim and Rachel talked things over and said that they would try and talk about things more so that they could make the marriage work. They decided to take a quick break in the City. While they were there, Rachel brought up the topic of starting a family together. 
After Rachel told Kit that they wanted to start a family, Kit announced that she wanted to go back to the city to finish her Uni degree. Kim tried to sound enthusiastic about starting a family but after various meetings at the hospital , it was clear to Rachel were Kim stood on the subject. Kim admitted that he didn't feel ready to start a family. Rachel was hurt by his decision and they ended up having another he arguement. 
Hugh could see that Rachel wasn't feeling great, so he invited her over that same day. She didn't want to go home and see Kim so Hugh said she could stay as long as she wanted. Hugh was asleep on the sofa when he heard Rachel crying in the bedroom. He went in to see if she was okay. It was clear that she wasn't. They looked at each other for a few moments before kissing! Rachel woke up and couldn't believe what had just happened. Hugh said they had to talk about things but Rachel just wanted to go. Martha walked in and knew something was going on. The next day, Hugh told Martha what happened with him and Rachel.
Things between Kim and Rachel just got worse from then on. They had given up talking to each other as all that seemed to happen when they did, was that they argued.
Hugh gave Rachel an ultimatum. He was going to Johannesburg and he needed to know whether she would come with him. While that was going on, Kit was trying to convince Kim that he needed to be honest with himself and tell her how he was feeling. 
Time was up and Rachel had made her decision, she was going to stay with Kim. Hugh left Summer Bay after waiting for a decision by Rachel.
Crisis point really came when Rachel told Kim about her and Hugh. Kim couldn't believe what happened. Kim also admitted to Rachel that he kissed Kit. Kim then asked the question of how they got to where they were. Rachel tried to reason with Kim that he had betrayed her trust too, but he didn't want to hear it.
After months and months of a sad marriage breakdown, Kim had to make a decision. Was he going to be with Kit and Archie in the City or was he going to stay in Summer Bay with Rachel? After going to the City to think about things, he chose to be with Kit and Archie. 
He returned to the Bay to get some of his things. Rachel couldn't believe how things had ended up. Kim and Rachel hugged for the last time before he left. And that was the end of their marriage. One that had suffered so much since the beginning but was portrayed so well by Amy Mathews, Chris Hemsworth, Amy Mizzi and Rodger Corser.
I'll miss you Kachel...