eight o'clock
As Burton went on alone , he muttered , `` Yes , I must have all arrangements carefully made . I expect we shall have a dangerous tussle , for they are not the class of men to give in quietly . '' `` It 's what I call a tall order , Burton , '' exclaimed Tom Ellison , who , with the Doctor , had been listening to the police officer 's plan to raid the Cave of Hydas . `` I am glad you turned up before eight o'clock , Burton , for it would be difficult to enter the cave and find our way about without your guidance . It seems a likely place to get one 's head cracked in the dark , '' remarked the Doctor . `` It would not be easy for you to get in , but had I been caught last night you would have found a clue to my whereabouts in the letter I gave you . However , we are all here yet , and I expect we shall get the better of Appoyas and his gang if our plans work out properly , and if they do n't , then , well -- look out for yourselves , '' said Burton , and he shrugged his shoulders .