The other two films are Dong Fangjian (1982) and Lan Jin Jin Ji Chu Dong (1985), and like this one, the two are also based on the true story. All three are about the Chinese Sea-launched ballistic missiles (SLBM) and its land-based derivatives. The other two deals with the failed ex-USSR's attempts to obtain the Chinese SLBM secrets the scientists in this movie were working on. In real life, one of the scientist was an ex-USSR agent, joined KGB in the 1950's in the era of friendship and cooperation between China and ex-USSR, when he was assigned to work with the Soviet experts sent to help China.