Lenina is so shocked and disgusted at what she sees at the reservation that she goes back to the room and goes on "holiday." A holiday is what the pre-geneticized people like to call it when they need a break from reality. What it really is a drug-induced coma, or sedative, that allows them to sleep off any anxiety they may feel due to an overwhelming situation. Huxley writes:

"Lenina felt herself entitled, after this day of queerness and horror, to a complete and absolute holiday. As soon as they got back to the rest-house, she swallowed six half-gramme tablets ofsoma, lay down on her bed, and within ten minutes had embarked for a lunar eternity. It would be eighteen hours at the least before she was in time again"(167).

Simply put, the reality of an unconditioned life of savagery was too much for Lenina. The smells, the filth, and the condition of how the people looked and acted was too much for her naive eyes to behold. She knew that they would be there for a couple of days and had decided not to participate in any further activities on the reservation.