The secret of the talking card (#2)

Five weeks ago, Alex and Einstein left for the missing parents of Alex - famous archaeologists for the whole world. Rebecca and Joe are terribly worried that they do not get in touch. Finally, Rebecca and Joe receive a short message from Alexander: "I"m returning tomorrow!" True, at the airport it will be clear that Alex not only did not find his mother and dad, but also disappeared ... Meanwhile, inexplicable in London: city buildings take off into the air one after another. Even the famous "London Eye" drowned in Thames! The police inspector Klash is sure that Alexander’s disappearance is somehow connected with the emergency in London. That"s just Rebecca and Joe are not ready to wait for an official investigation when their best friend is in great trouble. They will spend their own!
For secondary school age