Prime Suspect's 1970s spin-off has made its debut - but viewers thought it bore a striking resemblance to another hit show set in the same period.
ITV series Prime Suspect 1973 stars Stefanie Martini as Dame Helen Mirren's Jane Tennison at the start of her career in the police, but viewers compared it to popular BBC drama Life On Mars.
One viewer tweeting as @MaisonCupcake wrote: "#PrimeSuspect1973 This is going to be like less cheery version of Life on Mars."
@Leon80sRadford, tweeted: "Watching Life On Mars .... sorry #PrimeSuspect1973."
Some wondered whether Philip Glenister's Life On Mars character Gene Hunt might make a crossover appearance.
@leauk84 wrote: "I keep expecting to see Gene Hunt. #PrimeSuspect1973," and @alexleam said: "What point does Gene Hunt rock up? #PrimeSuspect1973."
Others found they missed the BBC series.
@Livvy_Jade tweeted: "Watching #PrimeSuspect1973 just makes me want to watch Life on Mars all over again."
However, there was praise for Martini's portrayal of the character Dame Helen made famous.
@HausofKubrick tweeted: "Young Jane is giving the iconic character a good go and I love the slight references to the woman she later becomes. #PrimeSuspect1973."
@DanWJonson agreed: "@Smartiniful Congrats on #PrimeSuspect1973. Filled some huge shoes brilliantly."
The programme's soundtrack was also a hit with the audience.
@Crispie1975 tweeted: "Cat Stevens and Joe cocker I'm enjoying the music so far in #PrimeSuspect1973."
@Dex_Starz said: "Loving the music! Such memories! #PrimeSuspect1973," and @tonypdickinson wrote: "#PrimeSuspect1973 Best thing about watching this is going to be the period music ... 70s music was awesome."