Orpheus in the Undergrowth - S2-E2
Plot hole: When Jeremy stopped to drink his water, which turned out to be vodka and which killed him via a heart attack, why did he hide himself away, surrounded by plants and only found by his mobile ringing? And why would he put the lid back on the bottle in the throes of a heart attack?
Plot hole: When Eddie finds the hammer that killed Cousin Jim, Rosemary and Laura are on his tail, so he rushes to the river, and so does Martin and the constable. Problem is: Eddie and the girls are on one side of the river and Martin and the constable are on the other side of a river that is impossible to cross where they are - there are bridges, but not there. So, if Martin and the constable were heading for the hammer, why did they go to the wrong side of the river? It's all very dramatic, as Eddie has to dive into the water, but it's ridiculous, plot-wise.
Orpheus in the Undergrowth - S2-E2
Plot hole: At the very end, Julia calls Matt, a policeman, at Helena's place, to tell him to come and help his mother and Rosemary who are being held against their will. But Matt doesn't have a mobile, so how did Julia know he was at Helena's place, so she could ring him there and save the day? No-one knew he was at Helena's and it's the middle of the night. Matt should have been in bed asleep.
Orpheus in the Undergrowth - S2-E2
Plot hole: When Jeremy is found dead from a heart attack, for some reason, the girls talk about him taking something that caused his heart attack, or someone giving him something to cause his heart attack. People have heart attacks all the time, and Jeremy had "a dodgy ticker", so there's no reason for them to only think it's a "suspicious" heart attack.
Orpheus in the Undergrowth - S2-E2
Plot hole: While the girls are trying to work out who killed Jeremy, Rosemary says she thinks it's Julia - Julia owns the flat that Jeremy and Marcia live in - so Laura says "Why would she want Jeremy dead?" And Rosemary says "To sell the house for a greater amount of money." But that's wrong: When someone dies in a house, the house sells for less, not more - not many people want to live in a deceased estate.
Answer: Regents park.