Added July 2021

Bob the electrician has left the UK in disgrace, leaving a trail of electrical calamities in his wake. Thanks to an embellished CV and a great deal of luck, he has landed a plum job at the European Travel Commission, authoring their new automated COVID vaccine passport app. This revolutionary software decides which travellers can be admitted to which countries by keeping track of the prevalent COVID variants circulating around Europe. Admission is based on which variants they might have been exposed to earlier in their journey.

Meanwhile, having collected several large jackpots on the fruit machines, Alice was able to get her faulty electrics fixed with enough money left over for a fancy, five-star escape to Portugal. She's downloaded the new app and now all she has to do is get there!

Bob being Bob, it would be fair to say that the new software isn't quite working as intended. Instead, it has marked each border crossing in Europe with one of three colours – red, blue or purple – and will only let a traveller cross a border of a particular colour if the most recent border crossed by that traveller was the previous colour in the sequence: you can only cross a blue border if you last crossed a red border; you can only cross a purple border if you last crossed a blue border; and you can only cross a red border if you last crossed a purple border. Travellers starting from the UK must also begin their journey by crossing a red border.

Can you help Alice get from the UK to Portugal in time to enjoy some lovely sangria and pasteis de nata in the Iberian sunshine?

Portuguese Predicament

Before you start, let me preemptively clarify some potential ambiguities:

Unlike most of the mazes on this site, this puzzle is not interactive, so you'll have to solve it in your head or print it out and use a pencil. Sorry about that.

The rules of this maze are equivalent to those of Adrian Fisher's Mathematica maze – which, according to SuperMazes, is permanently in situ outside Leicester University – but my aim has been to apply the same rules in a real life (ish) setting.

Having trouble? Here's a .

Still having trouble? You can view the if you are really struggling. This will ruin the puzzle for you, so I would strongly advise against giving up too early!