▁as ▁Lucas ▁ ▁Adri ana ▁M oc ca ▁as ▁Il ona ▁ ▁Maria ▁Roman ▁as ▁S anda ▁ ▁Cam elia ▁Maxim ▁as ▁Maria ▁ ▁Production ▁ ▁The ▁film ▁has ▁been ▁advert ised ▁as ▁being ▁" based ▁on ▁real ▁events ". ▁The ▁" true ▁story " ▁on ▁which ▁the ▁film ▁is ▁supposed ly ▁based ▁is ▁that ▁of ▁an ▁Aust rian ▁couple ▁who ▁were ▁murder ed ▁by ▁three ▁te en agers ▁while ▁vac ation ing ▁in ▁the ▁Czech ▁Republic , ▁but ▁no ▁concrete ▁evidence ▁has ▁emer ged ▁to ▁prove ▁this ▁tale . ▁ ▁The ▁film ▁was ▁shot ▁in ▁ 3 0 ▁days . ▁According ▁to ▁More au , ▁Oliv ia ▁Bon amy ▁had ▁suffered ▁from ▁cla ust roph ob ia , ▁and ▁so ▁during ▁the ▁scene ▁where ▁her ▁character ▁Cl ément ine ▁craw ls ▁through ▁the ▁narrow ▁t unn els , ▁much ▁of ▁her ▁performance ▁was ▁her ▁genu ine ▁fear ▁of ▁being ▁in ▁the ▁tight ▁spaces . ▁ ▁Re ception ▁ ▁On ▁Rotten ▁Tomatoes , ▁the ▁film ▁holds ▁an ▁appro val ▁rating ▁of ▁ 6 2 % ▁based ▁on ▁, ▁with ▁a ▁weight ed ▁average ▁rating ▁of ▁ 6 . 1 / 1 0 . ▁The ▁site ' s ▁critical ▁cons ensus ▁reads , ▁" S us p ense ful ▁and ▁t ense ▁from ▁start ▁to ▁finish , ▁the ▁French ▁horror ▁film ▁Th em ▁proves ▁that ▁a ▁lack ▁of ▁g ore ▁doesn ' t ▁mean ▁a ▁dear th ▁of ▁sc ares ." ▁ ▁See ▁also ▁ ▁List ▁of ▁films ▁featuring ▁home ▁invas ions ▁ ▁References