What did Dirk understand at the end of The Long Dark Tea-Time of the Soul?

Question

At the end of The Long Dark Tea-Time of the Soul by Douglas Adams, upon learning that Odin sold his soul (at the end of Chapter 28), Dirk realizes something (possibly about the lawyer and his wife, the Draycotts).

What did Dirk understand?

Answer 1

Dirk "solved the case", which in this instance means he understood finally why all of the events in the story had happened. Well, almost all of the events. He probably still didn't understand where the eagle came from.

Here's what Dirk figured out (essentially, some of the details he learns in chapter 30):

1. Before the start of the story, Odin, the All-Father, was a homeless person living rough in England, and he saw a commercial where an actor played a god to sell soft drinks, and he thought maybe he could do that to earn some money, since he is an actual god.
2. Odin makes his way to an advertising agency where he runs into Cynthia Draycott, who realizes that he is an actual god with actual powers, so she tells her husband.
3. The Draycotts realize they have a huge opportunity, but they don't want to make things too complicated and unwieldy, so, as Clive Draycott says in chapter 30,

It's like you buy a big property, and then you sell off what you don't want. That way you get what you want, and a lot of other people get what they want, only they get it through you, and they feel a little obligated to you...

...and money flows back to pay for our Mr. Odin's very, very, very expensive private medical care.

4. So the Draycotts draft a contract to purchase Odin's immortal soul and all the power that goes with it in exchange for Odin having a comfortable life in Woodshead with a constant supply of fresh linen sheets.
5. Toe Rag is the negotiator of the contract on behalf of Odin, and tries to pull a lot of tricks on the Draycotts with the contract, but Clive is experienced with entertainment lawyers and is unfazed and doesn't fall for any tricks. So Toe Rag then presents Clive and Cynthia with a "bill for his time", which includes a kind of penalty clause. It's not clear exactly what the penalty clause is about - perhaps delayed or incomplete payment, but the penalty itself is clear: beheading by the Green Eyed Scythe Monster.
6. Clive notices the penalty clause, so he uses the network of influence they have built by parting out Odin's powers to so many people to pass along the "bill" presented to him by Toe Rag. Basically, he finds someone who owes them a favor and says, "hey, if you take care of this bill for me, I'll do that thing for you that I know you want".
7. The "bill" from Toe Rag is now a hot potato. That means that whoever is holding it when the penalty clause comes due is dead. So each person who gets it makes the same kind of deal with someone who owes them a favor, and they pass the hot potato along.
8. Meanwhile, Thor has figured out something is wrong, so he is trying to get to Oslo to find the original contract or something. And the story opens with him trying to book a flight on a commercial airline because he had tried flying himself but ended up confronted by an RAF fighter and had to turn it into an eagle.
9. Around the same time, the penalty clause has come due, and the person holding the hot potato is not only a neighbor of the Draycotts, but has also contracted Dirk to come by to try to pass the hot potato to Dirk right before the deadline. The intention is that Dirk will be killed, but Dirk oversleeps and is late, so his "client" is killed instead, since he's still holding the hot potato.
10. Thor is getting desperate, and has now semi-accidentally turned Miss Pierce (Dirk's former secretary) into a soda machine, an RAF fighter jet into an eagle, and Kate's table lamp into a kitten. Odin has seen this (at least the first two, the third was not reported in any papers as far as I can tell) and knows that Thor is going to find out about the deal, so he sends Toe Rag to stall and distract Thor.
11. Meanwhile Kate who was a witness to Thor's tantrum at the airport has been kind of unraveling the mystery (and also not really understanding anything) by going to Woodshead and meeting Odin. She also met Thor. Hijinks ensued all around, a few jokes were told; some good, some otherwise; and a nurse at Woodshead was put on report. There was a strangely spotless desk involved as well.
12. Dirk is now trying to figure out why his client died, while also dealing with a Refrigerator That Must Not Be Opened and a swooping eagle (which has the brain of the jet pilot and is trying to get some attention and help - hence the swooping).
13. Eventually Thor gets desperate and figures out at least part of what's up and challenges Odin to appear in Valhalla. He has brought Kate with him. Dirk has also managed to follow his holistic methods and figure out how to get to Valhalla and the Draycotts have been ordered to attend because the contract itself is the topic of the challenge.
14. It's at this point that Dirk has a conversation with one of the gods of Asgard and realizes all of what has happened. He says, "I said it was all her [Cynthia Draycott’s] fault the moment I saw her. I didn't realize I might actually be right."