Well , perhaps not lost . They were simply out of place , time , and quite possibly their minds . It was relative , not that she was looking to relate . Different worlds , different times - she did n't know what to think or believe and the mess was too complicated to contemplate in depth when running on fumes .

Based on the preceding passage, answer the following question What may be the reason for " running on fumes " ?
They did n't get much sleep if any .