Question

新概念2第14课中这一句英语中过去完成时如何理解？

I had an amusing experience last year. After I had left a small village in the south of France, I drove on to the next town. On the way, a young man waved to me. I stopped and he asked me for a lift. As soon as he had got into the car, I said good morning to him in French and he replied in the same language. Apart from a few words, I do not know any French at all. Neither of us spoke during the journey. I had nearly reached the town, when the young man suddenly said, very slowly, "Do you speak English?' As I soon learnt, he was English himself!'
其中的这一句 I had nearly reached the town, when the young man suddenly said, very slowly, "Do you speak English?' As I soon learnt, he was English himself!' 我的理解是：首先作者在讲述一段有趣的经历，时间点在去年，这一句中，作者用了过去完成时，此时的时间点是 作者去年说话的那一刻，后面有个when引导的短暂的动作 said，到底是said这个动作发生在前还是reached在前，此时有两种理解：我们要到那个小镇时，那个年轻人突然说......，另一个理解是：那年轻人突然说......，我们快那个城镇了。我是不是应该说：when I had nearly reached the town，the young suddenly said …..
这个when搞得我很晕，我总是觉得如果reached动作在前，那就应该when I had nearly reached the town…….但文中明显我们要到那个小镇时，那个年轻人突然说......这样理解才对，这个when到底表示的是reached的动作的时间点还是said的时间点？为什么when放在了后面？
还有：He called Marry when I come in.这句是我在一本语法书上看到的一句话，书上说 进来在前，而打电话在后。按照语法书上说的，一般过去时表时的过去的时间点 动作要早于说此话时speaker所处的时间点，因此我觉得应该是 called动作在前，come在后。
求英语大神根据上面的两个例子帮对比详细讲解下，一直很晕，谢谢！

Answer 1

这是 when 的另一个意思的用法，“刚怎么样...就怎么样”，有点suddenly的含义。
如：I was just going to speak, when the bell rang. 我刚要讲话，钟就响了。（例句来自《英华大辞典》郑易里）