Three people on platform 13 at Tokyo Station—two waitresses working at the Koyuki restaurant and Tetsuo Yasuda, manager of a machine parts store—witness Otoki, who also works at Koyuki, boarding the night express Asakaze with a man from platform 15, which is located across from them. Days later, Otoki and the man, Sayama, are found dead by the seashore in Fukuoka. At first it appears to be an ordinary lovers’ suicide, but Shigetaro Torigai, an experienced detective in charge of the case, suspects something is amiss. The key is a bill from the train dining car which Sayama had on his person. Meanwhile, it turns out that Sayama was involved with corruption among government officials. Investigator Kiichi Mihara, who is handling the corruption case in Tokyo, heads for Fukuoka to find out what happened to Sayama. Then Torigai and Mihara discover that it’s possible to see platform 15 from platform 13 for only four minutes out of a day. Did Yasuda really see the couple by chance? The two investigators begin to suspect Yasuda, who was on platform 13 during those four minutes. But Yasuda has a perfect alibi that he was in Hokkaido at the time of the murder . . .

A masterpiece of intrigue and surprise, Points and Lines is regarded as a pioneer in the mystery novel genre that gave rise to a boom in detective fiction in Japan. It has been made into a movie and a TV drama several times.