From the start of this drama it was flawed. Set in Scotland the law requires the rule of corroboration ​so why would you send a senior detective ​on her own ​to investigate a murder without it.​ It is poorly written and to suggest a two billion Vanguard sub runs on diesel is laughable. Vanguard class subs are steam powered and being equipped with world beating sonar the system is so sensitive they can hear vessels over fifty miles away and yet the captain had to raise the scope to see the tanker. How did Jade get into the base without being stopped when Kristen had car stopped with dogs sniffing etc. There are too many inaccuracies, the sound is poor and this drama should have been sunk before production.