House of Secrets #2: Battle of the Beasts by Chris Columbus and Ned Vizzini

My name is Eleanor, and I should have made a better wish to get rid of Dahlia forever. Once again, Kristoff House has deposited us into another book, actually a combination of three different books, and the Wind Witch is still tormenting us. We're stuck in ancient Rome where Nazi robot soldiers have attacked the emperor's citizens. Brendan is enjoying his new post as the emperor's general, and he actually wants to stay in this world! It looks like we may also be stuck here after I destroyed The Book of Doom and Despair. However, there may be a way for us to return to San Francisco. We now find ourselves in the frigid, snowy German mountains with peaceful monks, surrounded by ferocious frost beasts. We'll probably be killed if we fight the monsters, but we'll be sacrificed to them if we don't. Fighting may be worth the risk, because the monks believe we may find the Door of Ways inside the beasts' cave and will be able to return home.

You should probably read the first book in the series before this one. It establishes the ground rules for the books and describes the ongoing conflict with Kristoff and his daughter. The most intriguing aspect of Battle of Beasts is the mixture of characters from different Kristoff books. We have the three kids and a WW I pilot from the first book joining a Roman gladiator to fight monsters, robot Nazis, and the Roman soldiers. The setting is a mixture of two Kristoff books, but the kids aren't sure about the third one. This third book offers the unexpected possibilities. The authors adds some tweaks to the characters. Cordelia had a crush on Will, the WW I pilot, in book one, but the Roman gladiator complicates things. Brendan's insecurities make it easy for him to be influenced by his new-found fame in ancient Rome. Predictably, the fame does not grow in the ways he expected, so a new conflict is created. Eleanor is the youngest sibling, but she takes a leading role in saving the day. She's the one responsible for using the magic book this time, although it's destruction complicates matters. A diary from Kristoff's wife is found, but the author doesn't reveal its contents until near the end. The secret was very unexpected, but its impact remains to be seen.