A 30 year old G5 P3 A1 comes to your OPD in exhausted state with labour pains since 12 hours and history of drainage of liquor 10 hours back. On examination her pulse is 96/ min, tongue is dry and coated. By PA examination it is term pregnancy with good uterine contractions and with absent fetal hea sound. On PV examination cervix is thick, 6-7 cm dilated membrane absent, big caput is present and station of head is + 3. Your most likely diagnosis is:-