Edition: Gollancz, 1985
Review number: 674
One of the most well known of Heinlein's early novels, The Door Into Summer is typical of the best of them. It is about the use of that staple of science fiction, cold sleep, to outlive a difficult situation in the present. Most candidates for this treatment are terminally ill patients who want to be woken when a cure has been found; but Heinlein's hero wants to escape the consequences of the theft of his business.
Some complicated adventures ensue, as his former partner drugs him to attempt to get his remaining assets through post-hypnotic suggestion, and then sends him through cold sleep anyway when his most recent invention - he is an engineer who has created the first household robots - goes missing. Eventually, he is able to return using a time machine and sort a lot of things out.
There are clear holes in the plot (why has his partner let him get away rather than drugging and hypnotising him immediately, for example), and it is a little difficult to keep track of what is going on, but the first person narrative is quite compelling. To someone interested in new technology, it is fascinating to see just how over-optimistic Heinlein could be in 1956 - household robots and cold sleep in 1970, while here we are in 2000 with neither of these developments. In the case of the robots, it is not exactly an overestimate of the rate of development of technology that Heinlein got wrong; the ones in this novel are based on vacuum tubes rather than integrated circuits - it is that the problem of fully automating housework is far more difficult than he imagined.
The Door Into Summer is entertaining if shallow classic science fiction.