James Nesbitt stars as DCI Tom Brannick in the crime series, which sees the Dunfolan police force attempt to track down a serial killer from the 1990s named Goliath.
WATCH: Are you enjoying series two?
Following the major cliffhanger at the end of series one, which revealed Brannick to be the murderer, series two opened with a flashback to 1998 which showed a much younger Tom, using de-ageing technology on actor James.
Viewers took to Twitter to comment on the flashback and James' digitally-altered appearance, with one person writing: "James Nesbitt definitely getting better with age that CGI was terrifying," while another added: "Mmmm - not entirely convinced by the CGI de-ageing."
A third viewer commented: "Can't stop laughing at that terrifying yet ridiculous filter on James Nesbitt."
Some viewers were left a little confused by the first episode, with one person tweeting: "Watched #Bloodlands tonight. Felt like I was starting in the middle of a story. Was thoroughly confused. But enjoyed it nevertheless," while another added: "It might be me (probably is) not concentrating, but does anyone understand what's going on in #Bloodlands?"
Some viewers commented on the de-ageing technology
However, many were glued to the screen and praised the gripping plot. One person wrote: "Excellent episode of #Bloodlands. Plenty of intrigue and intensity," while another added: "Great first episode of the new series of Bloodlands tonight on @BBCOne."
A number of fans also applauded James for his performance as DCI Tom, with one person commenting: "So happy that #Bloodlands is back on. #jamesnesbitt is a cracking actor," while another added: "Fast-paced already. James Nesbitt is amazing."
A third tweeted: "Always been a fan of #JamesNesbitt never fails to disappoint."
Many viewers praised the series two debut
For those who have yet to catch up on the new series, the official synopsis reads: "When the murder of a crooked accountant unravels a trail of greed that threatens to expose his identity as legendary assassin, Goliath, DCI Tom Brannick and the accountant's widow, Olivia Foyle must keep each other dangerously close.
"As they try to solve the riddle her husband left behind, and become more and more immersed in the puzzle of each other, Tom and Olivia draw in Tom's fellow officers DS Niamh McGovern, DCS Jackie Twomey and DC 'Birdy' Bird, as well as Tom’s daughter, Izzy, until deceit and betrayal force Tom to question just what lengths he will go to to keep his legacy intact."
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