Title: Geordie Shore OGs
Content:  recurring role in the first season, then became a full-time cast member in 2020. The third season premiered on 28 October 2020. Gaz Beadle and Sophie Kasaei did not return to the show after the previous season. Featured Aaron and Tahlia trying to save their relationship when they welcomed a new baby, Marnie's health issues, and Holly's wedding plans. In June 2021, the fourth season was announced and premiered on 13 July 2021. It featured Marnie and Casey facilitating their on-off relationship. Sophie also returns to the show as she develops as an entrepreneur. Holly grapples with the ups and downs of her upcoming nuptials due to the coronavirus pandemic, while Aaron and his girlfriend Tahlia face challenges after the troubled birth of her second child.
Title: Geordie Shore OGs
Content:  In May 2019, MTV confirmed a new Geordie Shore spin-off, featuring former cast members. Craig Orr, VP of commissioning and development at MTV International, said: "We're really excited to reunite viewers with some of the most influential and most loved cast members. We can't wait to show how life has changed for this lot since leaving the Geordie house and catch up with them as they continue to navigate their way into adulthood." The first season premiered on 14 August 2019. It featured Aaron Chalmers, Gaz Beadle, Holly Hagan, and Marnie Simpson. Production took place in Bedfordshire, Leeds, London, Newcastle and Newport. The second season premiered on 26 February 2020 and focused on Marnie's pregnancies, Gaz's girlfriend, and Aaron's professional career in MMA. Sophie Kasaei, who had 
Title: Geordie Shore (series 7)
Content:  last series to feature Sophie Kasaei after she was axed from the series following a racial slur. It was also the first series to feature Sophie's cousin, Marnie Simpson and included the brief return of Jay Gardner, who had previously featured in series one to three, and again during the sixth series for two episodes. Following Vicky's arrest, she was absent from the final half of the series. This series included the cast members taking part in a number of activities on their bucket list, new cast member Marnie isolating herself after breaking up the friendship between Gaz and Scott, and Jay returning to fix the drift between the cast members.
Title: List of Geordie Shore cast members
Content:  Thomas-Tuck and Guarnaccio had left Geordie Shore and would not be returning for the sixth series. On 9 April 2013 it was confirmed that former cast member Jay Gardner, who featured from series 1–3, would be returning briefly for the sixth series. The sixth series began 9 July 2013. On 12 July 2013 it was announced that Sophie Kasaei had been sacked from the show following an incident which took place in a nightclub where she used a racist term off camera. Sophie will have appeared in the show from series 1–7. On 13 August 2013, it was confirmed that Sophie's cousin, Marnie Simpson had 
Title: Geordie Shore (series 15)
Content:  The fifteenth series of Geordie Shore, a British television programme based in Newcastle upon Tyne, was confirmed on 8 August 2017 when a teaser video was released. The series began on 29 August 2017, and concluded after nine episodes on 17 October 2017. This was the final series to include Scotty T and Marty McKenna after they were both axed from the show, as well as original cast member Gaz Beadle following his decision to quit. The series also featured the brief return of Elettra Lamborghini, when the cast jetted off to Rome. The series included further twists in Aaron and Marnie's turbulent relationship, a newly single Gaz getting cosy with Abbie, as well as Chloe and Nathan's friendship facing its biggest strain to date. It also features the group visiting Rome, and Aaron taking part in his debut MMA fight in Birmingham.
Title: Geordie Shore (series 17)
Content: = Cast member is featured in this episode. ; = Cast member arrives in the house. ; = Cast member voluntarily leaves the house. ; = Cast member leaves and returns to the house in the same episode. ; = Cast member returns to the house. ; = Cast member leaves the series. ; = Cast member returns to the series. ; = Cast member is not officially a cast member in this episode. 
Title: Geordie Shore (series 8)
Content: = Cast member is featured in this episode. ; = Cast member arrives in the house. ; = Cast member voluntarily leaves the house. ; = Cast member leaves and returns to the house in the same episode. ; = Cast member returns to the house. ; = Cast member does not feature in this episode. ; = Cast member is not officially a cast member in this episode. 
Title: Geordie Shore (series 16)
Content:  The sixteenth series of Geordie Shore, a British television programme based in Newcastle Upon Tyne was filmed in September 2017 and began on 9 January 2018, and concluded after ten episodes on 13 March 2018. This is the first series not to include original cast member Gaz Beadle after he quit the show for personal reasons. New cast members for this series include Sam Gowland, who had previously appeared on the third series of Love Island, as well as Steph Snowdon. However it was later revealed that Steph had been axed from the show and would therefore not return for the seventeenth series. During this series, cast members Aaron Chalmers and Marnie Simpson both announced that they'd quit the show – therefore this was their final series. The series focused heavily on the love triangle between Abbie, Chloe and Sam, before Chloe and Sam finally make their relationship official. It also included former flames Aaron and Marnie coming to terms with living in the house together whilst both in relationships outside of the house, as well as Sophie and Nathan's struggles without their other halves.
Title: Marnie Simpson
Content:  Marnie Simpson (born 17 January 1992) is an English television personality. She is known for appearing on the MTV reality series Geordie Shore. In 2016, she finished in fourth place on the eighteenth series of Celebrity Big Brother, and appeared on the eighth series of Ex on the Beach.
Title: Geordie Shore (series 18)
Content: = Cast member is featured in this episode. ; = Cast member arrives in the house. ; = Cast member leaves and returns to the house in the same episode. ; = Cast member returns to the house. ; = Cast member leaves the series. ; = Cast member returns to the series. ; = Cast member features in this episode, but is outside of the house. ; = Cast member does not feature in this episode. ; = Cast member is not officially a cast member in this episode. 

Question: what episode does marnie come back in geordie shore?
Answer: 5.