Keypress Navigation for Strong Female Protagonist

strongFemaleProtagonistNavigation.js

// ==UserScript==
// @name         Strong Female Protagonist Navigator and Alt Text Reader
// @namespace    https://gist.github.com/briankung/092efc3a10e1f712752c
// @version      0.0.7
// @description  This lets you navigate the webcomic with the arrow keys. It will show you the mouseover text 
// from the current comic before loading the next one unless you hold shift.
// @author       Brian Kung
// @match        http://strongfemaleprotagonist.com/*
// @grant        none
// ==/UserScript==
 
var LEFT = 37, RIGHT = 39;
 
window.onkeydown = function(e) {
    var prev = document.querySelector('a[rel="prev"]');
    var next = document.querySelector('a[rel="next"]');
    e = e || window.event;
    
    var findImage = function(node) {
        if (node.tagName === 'IMG') {
            return node;
        } else {
            var childNodes = [].slice.call(node.childNodes);
            return childNodes.reduce(
                function(result,child){ return result || findImage(child) }, null
            );
        }
    };
    
    var comic = function() {
        var article = document.querySelector('article');
        return findImage(article);
    }
    
    if (e.keyCode === LEFT) {
        if (prev) { location.href = prev.href }
    } else if (!e.shiftKey && e.keyCode === RIGHT) {
        var title = comic().title;
        if (title) { alert(title) };
        if (next) { location.href = next.href };
    } else if (e.shiftKey && e.keyCode === RIGHT) {
        if (next) { location.href = next.href }
    };
};

Screws up on: http://strongfemaleprotagonist.com/guest-art/wednesday/

EDIT - fixed.