4 ▁as ▁the ▁final ▁install ment ▁in ▁the ▁franch ise . ▁The ▁film ▁was ▁re made ▁in ▁the ▁United ▁States ▁under ▁the ▁name ▁Qu ar antine ▁in ▁ 2 0 0 8 . ▁ ▁Plot ▁ ▁Re porter ▁Áng ela ▁Vid al ▁( Man uela ▁Vel as co ) ▁and ▁her ▁cam er aman ▁Pablo ▁are ▁covering ▁the ▁night ▁shift ▁in ▁one ▁of ▁Barcelona ' s ▁local ▁fire ▁stations ▁for ▁the ▁document ary ▁television ▁series ▁While ▁You ' re ▁S leep ing . ▁While ▁they ▁are ▁recording , ▁the ▁fire house ▁receives ▁a ▁call ▁about ▁an ▁old ▁woman , ▁Mrs . ▁Iz quier do , ▁who ▁is ▁tra pped ▁in ▁her ▁a partment ▁and ▁sc ream ing . ▁Áng ela ▁and ▁Pablo ▁accomp any ▁two ▁of ▁the ▁fire fig h ters , ▁Á lex ▁and ▁Man u , ▁to ▁the ▁a partment ▁building , ▁where ▁two ▁police ▁officers ▁are ▁waiting . ▁As ▁they ▁approach , ▁the ▁old ▁woman ▁becomes ▁ag gress ive ▁and ▁attacks ▁one ▁of ▁the ▁officers , ▁bit ing ▁his ▁neck . ▁As ▁they ▁carry ▁the ▁injured ▁officer ▁down st airs , ▁they ▁find ▁the ▁building ▁residents ▁gathered ▁in ▁the ▁lo bb y . ▁The ▁police ▁and ▁military ▁have ▁se aled ▁off ▁the ▁building ▁and ▁tra pped ▁them ▁inside . ▁ ▁As ▁people ▁begin ▁to ▁pan ic , ▁Á lex , ▁who ▁remained ▁up st airs ▁with ▁the ▁old ▁woman , ▁is ▁thrown ▁over ▁the ▁st air case ▁rail ings ▁and ▁crit ically ▁injured . ▁Mrs . ▁Iz quier do ▁then